I developed a clear roll just the other week. Picked up & developed an unexposed roll.
Hopefully I want do that again. Now I have a box I throw my exposed rolls in. Anyway when you clip the leader off your roll use that to test your fixer & you will quickly know if it's good, plus you can get your times from that x by 2. Always set your chemicals in the same order each time you develop. From left to right I go dev., sb, fix, wash. I never make a mistake that way. Some people don't like the results, but thats whats so nice about HC-110. You can mix up what you need to do a roll of film & the stuff last almost forever. One shot & it's gone. Try some Perceptol, just for fun. It's a fine grain developer & you might like it.