Grandpa would net carp out of the river. My grandma would gut, scale and cut off the head and fins. throw the carp in a pressure cooker. Get the meat out pick out the large bones and make patties with cornmeal, egg and milk with salt and pepper. The little bones were soft. Reminds me of canned salmon.

I remember these being very tasty. I have never tried it myself. Grandma was a great cook.

I've used a crockpot overnight and that disolves the bones as well. Added breadcrumbs and eggs, fried it into fish cakes. But I swear those fish are about 90% bones and guts.