When I cut for a contest, or just for asthetics, I make my pwo shake just about the last thing I mess with. I try to keep that intact as long as I can for obvious reasons.
As your caloric intake decreases, it will become necessary to adjust it. Then I do this by the same method I use in normal caloric cuts. Slowly and carefully.
I may start out by cutting 1 tbsp. of dextrose, then another, etc. But you will still need a pwo recovery. I always keep my protein intact thoug in my pwo shake.