Aging meat helps to tenderize it and I used to do mine in an ice pack in a huge cooler , drain water and rotate every day for 3 or more days . Never found a way to get the silver or tendons out easily , but it helps if it’s cold and firm when you carve on it a lot . Took my inedibles back to the woods sometimes and sometimes I took them to the dumpster at work as well .
Tried about a million ways and processors and in the end I have 2 I like and trust and just hand them my buck and a hundred or so and let them do it now as I have gotten a bit lazy and less poor than I once was ....lol