I had lots of fun developing Black and White film with commercial chemicals. They are cheap enough, but do expire. Caffenol works reasonably well, and because it's made from dry ingredients doesn't really go off.

The main issues I had were around the reels for loading film ready for the tank. 26-frame rolls were usually fine, but 26-frame often buckled. Stainless Steel reels were much worse and stuck together. For sale if anyone is interested!