Chicken stock from frozen bones from Lion

This is not our normal way to make stock, but I noticed that Lion sells frozen chicken bones for something like $0.70 / lb.  I bought almost 3 lbs, dumped them in the slow cooker with 1 yellow onion, 2 cloves garlic, 12 C water and 1/2 tsp salt.  Cooked on low for 10 hours.  Came out great!