Duck waxing and processing leftovers

Hi there question for y’all- after processing your ducks what do you do with the leftover wax? I’ve heard you can reuse it, can anyone share their setup for how they do this and how many times it can be reused, and what you do with it after it’s ‘done’? Would reusing the wax potentially invite pathogens, and/or are there rules about refusing it when you are processing for market?
I’d also love to hear what you do with all of the leftovers- I’m thinking about a biodigester and I’d love any advice.
Thank you!

Here is a thread you might enjoy:

https://permies.com/t/148071/Making-carcass#1158598