Could I put the jars in my crock pot? (Any danger of posting next from the hospital ER after the jars explode and send shards of glass around my kitchen?)

The danger of trying to do this in a crock pot is death from botulism.

This is not a slow-cooking procedure. It says to BOIL the jars for 2.5 hours. That means a fairly hard boil for the entire time, but even that is NOT SAFE for processing meat. Water-bath canning is only safe for jams and jellies that contain a lot of sugar, or tomatoes or pickles that contain acid, and some health authorities say it is not safe even for those.

The safe way to process meat is to cook it fully and then can in a PRESSURE CANNER.

However, confit is a traditional method of preserving fatty meat without refrigeration. The classic way of making it requires cooking the meat in its own fat for a long, long time, so that microorganisms and enzymes that cause spoiling are destroyed and so that the fat seals air out. Traditional recipes do not even require canning - for an example that includes every possible detail, check out the confit d'oie (goose) recipe in Mastering the Art of French Cooking.

Really, I do not recommend this recipe at all.