Maybe a little more pre-spray than normal. Definitely more time than normal. Takes time to work thru all that material. Charge a surcharge, if you feel you should be compensated for the extra time.
being that i myself am new to OP'ing, i wouldn't touch a Frieze without a Tuway Thinone aka Durapad. i wouldn't want it to tip bloom and have to replace the carpet out of my pocket.
Tuway Thin One cleans the Frieze beautifully.
now if you are talking about the OLD style shag, i am talking about if this carpet is 20-30 years old, then i would be more comfortable using a cotton pad on that, just keep it lubed well as Mark said. but for today's "shag", they are called Frieze and aren't made very tough.
