I use Rescue Remedy in my parrots water bottle. You only add a couple of drops- I think their bottle is 16oz- so I add 4 drops. And from everything I have read- even if I were to 10x that- it will not change the affect, hurt them, overdose, whatever….it only wastes the extra drops that you used. It has a maximum efficiency and it does not increase with more Rescue Remedy added.
I have seen improvement in 1 pair of parrots (the african grey male was plucking when I got them) and Jahazi looks much better now.
Have never tried it with a bunny- but I have noticed that the RR has an “alcohol” base- so I am unsure of a rabbits response to direct admin on a daily basis if that is how it is being used. I know that you can also add RR to water- and I use that to mist my Grey’s. If they don’t mind it on the papaya tablet- that sounds like a great way to give it. I don’t think it is sweet- so they probably won’t be excited about eating it out of a syringe like Metacam or some Anitbiotics. Plus the dropper for the RR is glass!!