We just had this question come up at the sanctuary and our rabbit vet said papaya and pineapple in all their assorted forms, pills, fresh, dried...is a myth for helping dissolve hairballs.....the best thing she said is to brush, brush, brush......

The brush should NOT be one of those with the thin metal tines (even though the is a picture of a bunny on the package)..... a rabbits skin is fragile and tears easily.....a flea comb works great as does dampening your hands or a glove or a cloth with water....the water keeps the hair from flying all around.