I usually walk on these especially if the customer asks "can you give it a once over" while I am there cleaning their living room. I need to prepare myself mentally for these!
First you'll need to vac it to death using your crevice tool on your hands and knees. Then rake it, then vac it. Vac, rake, vac, rake.... you get the idea.
Then normal hwe method using a hand tool.
Drying can be a pain in the harris though.
Even with all the vaccing, raking and hwe you'll never get rid of all the crap in the base of the pile. If the customer looks between the pile they'll see all the curd.