i have marinaded chicken and beef in braggs acv. its great. i recommend doing it for a full 24 hrs, if you do it for only 8 or 10 its not the same. both the acids and the mother in the acv break down and pre digest the meat. i throw out the marinade, altho you could in theory use it. i also like to add garlic or cayenne to the marinade.
cut the meat into very very thin strips so the acv can get to all of it. put it in a mason jar and fill with acv til the meat is completely covered. put in refrig for 24 hrs, drain, cook at low temp. i cook it with veggies.
the chicken works out the best, it is SOOOOOO tender once cooked, it literally melts in your mouth. the beef is also good, but doesn't get quite as tender. i have never done fish or lamb. if you try it, please post i would be interested in hearing your experiences.