Where are you staying? At OKW and SSR, the laundry rooms are located near the pools. At BWV and VWL, they are located on the first floor of the villas. At BCV, they are located on the 4th floor of the villas.
There are not that many washers and dryers available, so you may have to work around the other users. You can't just leave your clothes in the washer or dryer and leave them either. There is no cost to use them for persons staying in studios. You must provide your own laundry soap and other laundry items such as fabric softener or dryer sheets.