If anyone needs help doing this I will be more than glad to help you out in showing you how, yes with the rock trick, but the fastest I have beaten him mind you is around 50 mins when using this cheap trick.
basically he's not walking through the acid spouts he needs to walk through them in order for them to close he also soaks them up and thus damaging him. I can post a link in this reply as well that will help you out my fastest time now was 35 mins.
We fight Gee all the time as he was intended to be fought with no camping behind a rock. We also make sure all the worms are dead when he dies. Sometimes he freezes and sometimes he does not. It has nothing to do with worms. We have come to the conclusion
that it freezes based off of what he drops.