Indeed, a rule of thumb (or another part of a human body): if something does not go in or out – relax, lube it up and do not use much force and sharp movements. That, actually, works in many completely not related to (self-)bondage cases. Forget one of the “ingredients” (e.g. use lube but make a sharp movement), and the consequences might be even fatal. This is how I made leggings from latex tights and covered the floor in the hotel room with ….
You can have an idea if you read this post: Self-bondage-session-67 thoughts, bondage gremlins or Mr. Bean for a week (still need to post this session).