Outdoor stores and the like rent sleeping bags all the time. Im sure you can rent something like a chocolate fountain from one of those party supply places. A basic fondue set (which you could probably rig up with what you have in a house) is likely too cheap to justify the overhead of renting. That is sort of the classic borrow from a neighbor if you can.

Um why not?

Do you never leave your house? You have never eaten off a plate you don't own? Never been to a restaurant? You've never slept in a hotel or at a friend's house?

(I went rouge and bought both dishes and blankets from Goodwill so don't come over to my house.)