I mean this was crazy hard! Like hanging with all my body weight trying to pull the pelt off. So, if I have to cull older animals in future, woud hay only fast for a few weeks and maybe a full 24 hours of water only prior to dispatch maybe help to create some room?
I kind of suspect it would not make a huge difference. No one at my place likes to harvest mature animals (5-6 months and over), even though they are the ones with the mind-blowing prime pelts, because it's so hard to get them to let go of their hide. My middle daughter is currently my harvest help and she literally hangs on them, even with a sharp knife to assist. The older the rabbits get, the harder it is, especially bucks. Tons of fat does seem to make it worse, but most of my rabbits aren't
too fat and the older ones are all hard.
There is a nice technique with an angled knife that helps overall, but when it comes to the tight places, you just have to haul on it.
As far as fasting them to get rid of fat, my thoughts are that the ideal would be to just feed them a diet that doesn't allow them to get overly fat in the first place. Rabbits need
some fat to be healthy, but excess isn't good for them, either, and I consider it money down the drain to buy pellets to make fat. It would be different if I had something I particularly wanted the fat for, but since I have lots of other sources, I don't. I do render rabbit fat when I get enough, but mostly because I don't like waste.