I'm with Floyd on this one.
I use exactly the same technique on POP noise as well - words starting with "P" or "B".

Having said that, I always try to get people to sing past the mic from about eight inches away, rather than into it.
It avoids proximity effects and I prefer this to a POP screen. I don't get any appreciable drop in signal and it
avoids a lot of problems.

ROG.