Pad cleaning

You could use dawn. Or an all purpose cleaner.

Spray it with some all purpose cleaner, knead the pad so that the cleaner begins to break down the products. Let sit for 5 minutes or so then submerge it in warm / hot water again kneading it so that the contaminates are dissolved and flushed out.

Depending on how soiled the pads are I might add a little all purpose cleaner to the hot water to give it more cleaning power.

Once you're satisfied rinse thoroughly in hot water and allow the pad to dry. I like to place my pads face down on a terrycloth towel and press them flat so the towel absorbs as much water as possible to aid in drying..

+1 on Bobby's suggestion

If you have some spray pad cleaner that'll help. I use Megs APC+ along the way to keep them moist then a little Dawn while washing and they are good as new. Did find a little trick when drying that I like... I take a plastic cups and sit them on them do dry. It lets air circulate underneath better than having them lay flat. But that's just me!

I've never used a dedicated pad cleaner. I soak my pads in a sink/bucket of hot water with an unmeasured amount of Dawn dish soap. Let them soak overnight, then rinse them while squeezing out the product with my fingers. Dry them face down on a grit guard and they're as good as new.