When in goo form, sleeping can always be a risk from others using that time to get you in a container without you noticing, and saving you for later. Some (Looking at you, Aver) know how to prevent this, others do not or are too busy panicking at the slurp to realize they could prevent it.

Kob here caught Goocour off guard and don't think he'll be able to get free before the slurpening...

Art by  Kobada