Yes, drastic things happening are fairly common in dreams. Anything can happen.

I just see one problem with your RC. That is that you won't always have two clocks in your dream. You can of course summon them or look around to find two, but it's very possible that you won't find any. You should take a look at the dild tutorials and see the kind of RCs they recommend. Most of them have to do with your body since mostly you have a dream body so you don't have to depend on some object that may or may not be present in the dream. Your current RC is a good idea, but it won't necessarily be feasible to do in a dream.