Remember how Band of Bees was a powerful treasure to get?  Well Vile concoctions is basically that, but better.  Here are the creatures that become board-wipes with this hero power:

Tentacle of N'Zoth, Unstable Ghoul, Wild Pyromancer, and Baron Geddon

Ideally you play one of these cards and than give it poisonous with your hero power.  Their effects that damage all minions will also be poisonous, so it destroys all minions essentially.  This will also make your minion stealth most of the time because you played your card on the same turn, so don't count on Unstable Ghoul having taunt!  This is actually a good thing though, because you want to set off your board wipes on the next turn so that you can have a free board.  If your opponent can set off the board wipe they get to develop on that turn, so giving stealth is actually a huge bonus.

Other uses for the hero power

Any 1 drop minion is good because you can make it poisonous and trade into bigger minions from your opponent.

Knife Juggler can snipe opponent's minions while he has poisonous.  Remember to not attack with him so he doesn't lose stealth, and if need be keep re-applying stealth every turn with your hero power.

Applying stealth can also sometimes be useful, though it is not the main point of the hero power.  You can use this on minions that you want to bounce later (Like Jandice Barov or Loatheb), but want them on the board a little longer to trade or go face with.  It can also be used on Knife Juggler and Baron Geddon to save your minion destroying engine from opponents removal or trades.  Just remember the stealth wears off after 1 turn, so re-apply as necessary!

Animated Broomstick is an all-star, as it often is.  You can use this to rush in one of your board clear creatures to clear a board on demand, rather than having to wait a turn to attack in.  You can also just use it with your hero power for a 3 mana 1/1 with rush and poisonous (aka, kill a creature).

The rest of the deck

Due to having such powerful board wipes and strong removal, I believe a control style shell is the best way to go to round out the deck.  Rogue has a lot of powerful value battle-cry minions right now, so cards like Shadowstep and Tenwu of the Red Smoke are great at abusing those battle-cries.  Alternatively, if you are against aggro you can re-use Armor Vendor to heal or Loatheb to stall for extra time.  The signature Treasure, Ace in the Hole, can be used after a shadowstep or Tenwa turn to get tons of value (you get a new copy for each time you played each card), or just to get extra healing from armor vendor against aggressive strategies.

Alexstrasza might seem a little off from the rest of the deck, so let me explain: She is a card picked to help the deck as the run continues. 

When health totals rise up to 40, she becomes extra powerful by setting your opponent to 15.  You can easily set up lethal by doing a double Jandice turn (with something like shadow step) and then alex the next to kill an opponent out of no-where.

She is also an okay healing card in the early games, where healing to 15 might be what keeps you out of range of a weapon rogue.

Finally, she has lots of good synergy with passive treasures.  If you end up not having great passive treasures to pick from you could end up with the one that reduces cost of all dragons by 2, or Sceptor of Summoning (all creaturs that cost 5 or more cost 5), or Disks of Legend (Summon copy of all played legendary minions), or Dragonbone Ritual (Reborn all played dragons after 3 turns of being dormant).  Technically she also has synergy with Dragonblood, but please don't ever pick dragonblood, it is terrible in this deck.

Replacements

Okay, 6 legendaries is a lot to ask for.  Having all the legendaries will make the deck a lot better, but there are replacements if you are missing some.  Shadowcaster can substitute for Tenwa or one of the value 5-drop legendaries.  Steward of Scrolls can replace one of the 5-drop legendaries.  Novice Engineer is another fine card that can help you dig to your other value cards, just beware that fatigue can hurt in the early games against other control decks!

Playing the deck

This is a very difficult deck to play!  Don't fret if you mess up, or it seems like you are doing terrible at first.  There are many aspects of the deck to master:

1.) You are a control deck, so learning how to use answers according to any given matchup is key.  If you are against token druid, for example, try to keep their board clear to not die from savage roars or Arbor Ups.  If you are against a slower mage elemental deck, try to save a board wipe for their Fireworks finalle card (the one that summons a bunch of 8/8s).

2.) Using the hero power.  It is not an easy hero power to use.  It is easy to forget that the combo gives stealth.  Sometimes you want to play minions fast so you have something on the board to give poisonous too, and other times you need to save cards for combos.

3.) Combos and bounces.  Knowing when to use Tenwa and shadowstep and Ace in the Hole can seem daunting.  Once you know your opponents deck, try to identify the cards you wish to play multiple times.  For example: against aggro try to save your bounce effects for Armor Vendor.  Against slower decks try to save your bounce effects for your value cards.  And against all matches- remember that sometimes it is best to not hold onto your bounce cards and use them just as tempo-plays (Tenwa is a 3/2 for 2 in a pinch).

Treasures to look out for

From Pool 1: Sticky Fingers, Recycling, and Rocketboots are really useful.  We generate a lot of cards in this deck for Sticky fingers, having the extra hp from recycling helps us play all of our value cards, and rocketboots is very powerful with our hero power to give rush to poisonous minions. 

From Pool 2: Battle-cry totem is the dream, as the deck has a big focus on battle cry minions.  Disks of Legends and Emerald Goggles are close seconds.

Buckets to look out for

Having a high quantity of board wipes in the deck is key to going far.  Watch out for wild pyromancers and beron geddons, which do appear in some of the custom buckets.  Battle cry synergies is another bucket that goes well with the deck.  Do not pick the weapon buckets, as this deck has no weapon synergies!  Other than that, try to compliment your deck based on what passive treasures you got.  (minions if you got recycling, legendaries if you got Disks of Legend, ect...)