Papaya has the highest concentration of protease (enzyme), Papain commonly used as a meat tenderiser. Meat is a protein just like the fur you bunny ingests as it grooms itself or partner. There are other sources but I have found this to be the most effective. Kiwi fruit has Actinidain, a protease that also breaks down protein & pineapple has Bromelain, an enzyme that also breaks down protein.
Overall we have found that Papain is by far the most effective at moving the fur. 
We reccommend a weekly dose to help keep the fur moving trough. yu can mix it into anything as long as they have it. I make up fruit juice ice cubes for some or mix into crit care. you can also disolve into a small amount of liquid & syringe if you have multiple bunnies. The only alternative at the moment is the dry papaya seeds & grind yourself. 
 
Papain is extremely hard to purchase at the moment so we have imported it from overseas & broken it down into smaller bottles of 20 capsules.
The original label is include & a link to the manufacturers website.
Papaya has the highest concentration of protease (enzyme), Papain commonly used as a meat tenderiser. Meat is a protein just like the fur you bunny ingests as it grooms itself or partner. There are other sources but I have found this to be the most effective. Kiwi fruit has Actinidain, a protease that also breaks down protein & pineapple has Bromelain, an enzyme that also breaks down protein.
 
https://royaltropics.com/papaya