HDI I agree 100% with you as I meant to say only ever do this on SNOW and ICE. I'm fairly convinced that ABS is a handicap on ice. If you are on ICE chances are you are stuffed anyway but surely the ABS will back off to the point where the brakes are not applied at all so cadence will fool the ABS sensors momentarily. I am prepared to stand corrected though and will read any counter arguements or theories with interest.
Gravel is another situation where the banking up in front of a locked wheel can slow the car up more quickly than the ABS would otherwise let you. (I'll have to wait till it gets icy and try this one out!)

If only ABS was more clever.