I wash my pads in a bucket of warm water. With latex gloves on, I rub all excess wax of the pads in the bucket of water. I then wring them out in a towel wringer. I have been cleaning my pads like this for years.
I put them in the washing machine on the gental/handwash cycle with some liquid tide & simple green, if you have a soak cycle use that before running it through the wash. Air dry then store in a ziplock baggie. Works great even on dried on crud.