Interestingly, after one sleep cycle you can just walk out of the room as it will be unlocked, get your stuff back, and even barter with Elise normally. If you leave and come back, he ends up repeated the sleep potion thing. So it's less "escaping" and more "take a nap then just walk out doing whatever". For the most part, Elise's clinic is really useful for safe and free leveling due to him providing free bedding and food during the pregnancy (so just schlick a bunch to level up while freeloading).