This liquid was a cloudy, white substance that could be mixed in a drink or used as a contact poison. A single dose typically cost 300 gp.
A victim exposed to this substance experienced numbness in the limbs that could range from annoying to debilitating. If not quickly treated (or resisted), it soon got worse and even affected the victim's thoughts, impairing their judgement.
Elsk Thavarask, the proprietor of the Missing Minotaur tavern in Everlund, circa the Year of Wild Magic, 1372 DR, was known to use this substance to quickly put down extremely rowdy customers. He would also sell it to people he trusted.