I might be able to help out with rev whirl. As for rev whirr, well thats a whole other beast that I personally think is close to impossible (or at least bloody hard).
k, been drilling this a fair bit so...
- Low staright set. (thigh to waist high)
- plant setting foot as fast as possible.
- settle yourself, watch how high you did set (esp for conseq)
- When the bag is about thigh or knee high start the dex.
- Do the dex very fast (unlike whirl, rev whirl has to be done very low)
- As your dexing get your stalling clip in position and fully cranked
- cushion the stall as your dex foot slams the floor (with your toes)
- set low again
- repeat
A few extra things.
try to stay ontop of the bag and balanced.
The dex is easier if its slightly behind you
So for far conseq you want to plant quick and position yourself so the bag falls slightly behind you on the opp side.
If you like rev whirling rake have a look at TNT sessions (Jorden). He does one in that (thanks Ian for pointing that out).
I personally think its an ugly move because it looks like your just hopping over the bag and doing a toe stall. However if you make it look more X-Body rake I'm sure it would have its charm. Regardless its still quite a simple raking move if you think of it the way Jorden does it (just a hop into a toe stall).