I can't stand the pith on citrus fruit. Canned mandarin oranges seem to have their segments magically removed from the outer membrane that surrounds it. I know how to supreme a citrus fruit, and that is what I do when I want to eat one, but the canned ones don't seem to have been cut.   Does anyone know if there is a process that accomplishes this, that can be done in a home kitchen?  
This may sound ridiculous, but I cook the meat to about half-done before I trim it. Then just use a filleting knife, the same one I use for fish, and I insert toothpicks to the depth where they encounter solid meat, so I can judge how thick the fat is. Then I just fillet the fat off, using the toothpicks as a depth guide and removing them as i go, and I peel the sliced fat back with a fork. You should be able to get it all off in one sheet. 