If you do it, the niche is to do it on farm. Once you got a customer base, you could get a trailer and get it inspected depending on the state you're in. This is the future and it makes meat taste better.

Likely you'd end up wanting to partner with someone who can handle all of the offal in a compost pile or someone with chickens and pigs. Feed the pigs all the waste from the other animals, feed chickens all the waste from pigs. If your customers don't want the fat, keep it and get yourself a lady who will turn it into candles or soap.

Definitely hard work, but once you get your legs under you, if you wanted to teach, it's a highly sought after skill which you could probably fill a monthly class with.