I just recently got into buying whole chicken for our home cooking needs, and someone showed me an excellent recipe for a simple slow cooker chicken. So after buying a two-pack of whole chicken, I slow cooked the one and divided up the other as I had been doing; I've got the breasts, thighs, drumsticks, and wings frozen, and I'm keeping the back, bones, and any miscellaneous muscle that might have been left separate. Now, after doing the slow cooker step on the other chicken, I was left with juices, bones, and fat; I've got the juices and fat chilled as a stock base, and have saved the bones in the freezer.
My simple question: can I take the back and such from the one chicken, combine them with the bones from the slow cooker one, and make some additional stock later on? Or does the carcass need to be cleaned further before trying to make stock from it?