I frequently hear people say RCs in dreams dont make you lucid, but just confirms it. But I must disagree with that. I am on vacation and walked into a new bathroom, and did an RC, since unusual bathroom situations are a dream sign for me. I discovered of course I was indeed awake. Last night I dreamed I "had an accident" and had to clean up in the toilet. Just like in real life I did an RC and as I did in RL a few days earlier. I honestly thought I was awake, although considered the possibility of being in a dream in both situations. I was quite surprised the RC failed and was going to keep checking when I vaguely recalled I had been sleeping recently, so then knew yes I was dreaming. Both situations the RCs were the same and expectations were the same. I did not have a prior suspicion I was dreaming.