Hand rubbing isn't a reality check its a stabilization method
you feel your dream body via the hand rubbing and stabilize
this will work even if you have just entered the void and are blind
you can still feel your hands, and wait out the blindness

I just woke up from a dream where I was checking my eyes for blind spots by holding up my hands (similar to a reality check) but since in this test I was expecting to see parts of missing fingers that is what I saw. Since I was missing pieces of fingers the blind spot check was a pass, never thought of reality check or to count how many partial fingers I had

As I would move my dream hand thru my dream-blind spot the fingers would disappear (partially) and then reappear
should probably post this on in the stupidest ways I missed becoming lucid thread