I wash mine in the bath with the showerhead. Harsh spray setting. Hose down repeatedly. Shampoo and condition as human hair if needed. Mostly just warm water gets it clean though. I then put a chair in the bath, hang pad on the back overnight, then transfer to the airing cupboard once it has stopped dripping.
Mine is just the sheepskin without the cotton backing.
I wash with Christ cleaner in the bath or large container and then plenty of rinsing. No spin just squeeze what water I can and onto a drying rack. They can take a few days to dry but come up like new when brushed out.
Look after them between wears by airing out the sheepskin side after every use and brushing down.