Imho papaya doesn't do much. Theoretically yes, in laboratory settings, but not in real life. Neither does pineapple. But as long it's not given in a form that contains a lot of sugar, like fresh, canned, or dried, it shouldn't do harm. I wouldn't rely on that, hair is **** hard to dissolve.
A handful of sunflower seeds is a lot of calories, yes, they can eat them, that's about what you would give a doe nursing a big litter. So not a every day preventative, but imo ok when there are problems.
In case of an acute digestion issue due to too much hair my vet gives 1ml of paraffin oil (it's a bit controversial due to the risk of inhalation), then, when something is off that way, I now would rather try sunflower seed oil soaked into a little oatmeal. If the rabbit is still eating.
Apart from going through the fur with my fingers and plucking what is lose, sometimes with a little damp hands, going back and forth, I also use one of those wire brushes with little balls on the tips, pretty much only thing that works for mine. Apart from the pet safe trimmer when there are knots or mats. I try to avoid scissors, there were accidents.
I try to make it a distinct ritual, I don my protective gear (my 10yo is a vicious biter), announce that it's time again, get her or whoever needs it and do whatever is needs to be done, no discussion or apologies, and finish with a treat. I try to not bother them when just petting them, or passing by and seeing a lose tuft. I think that way it doesn't create as much trust issues like when I would try to get fur off every time they come into reach.
