Pad dusting is due to product not being removed from the pad in the wash and rinse phase..
I totally agree with Kosmetikwerks above - Snappy Clean -
I have used this for over 10 years and it has never failed to clean my pads and rinse completely out of all kinds of foam---
My process is to put a packet in a 5-gallon bucket with 3-4 gallons of water.
Soak the pads, push them down into the solution so they absorb the Snappy Clean.
Take them out 1 at a time, when its time to clean them, and wearing nitrile gloves, knead the faces of the pads together, squeezing them in the solution to release the material, and absorb more cleaner, then rinse them by hand, kneading them under the faucet, until only clean water comes out with no soap...
Snappy Clean is very low foaming, so this is a real benefit along with just perfect cleaning of the foam...
Then, set them on edge so that they get air all around them, and hopefully if its warm and good air circulation, they will be ready again in a little over 24 hours or so..
Good Luck !
Dan F