I was deliberately trying to avoid writing a review for the Laundry Room as talking about it really defeats the purpose of the secrecy surrounding a "speakeasy." But now that 50 other yelpers blew Commonwealth's cover I might as well throw in my two cents.
To get in, you need to text a secret number which changes pretty often. Upon arrival you get a text for a rendezvous spot inside Commonwealth where-after your party is led to the secret door in the back. The speakeasy is pretty small and very private. Service has always been excellent and the small trays of popcorn are delicious.
Now just to be clear, this is not the place to order a Bug Light or vodka tonic. The Laundry Room features a craft drink list all made on the spot and are unlike anything else you get can get in town. They put together a nice list libations, my fave: Rattlesnake featuring absinthe, rye whiskey, lemon, and egg whites. Each one of the drinks is $15. While $15 may seem a bit high, each drink is unique and definitely worth it.
Tip: no pictures of the Laundry Room! It is a secret after all.