I think the answer would be that M-Power continues cleaning and breaking down and splitting for upto 14 days, i personaly extract afterwards and this is also recommended by the supplier, however ive heard of cleaners who spray and agitate under chairs and sofa's then move sofa back and just leave it, they then just rinse the visable area, in my opinion for M-Power best results are obtained by pre-vac, accurate dilution at 120-1, good heavy spray, cursory agitation with a duo or similar, good dwell of 10-15 mins, reapply with a light misting if the carpet has dried when you are ready to extract. I also agree that its better on wool than polyproalene.
Dene