We have a pressure washer, but rarely use it. However, we have several fire hydrants and an adapter, so we just drag a long heavy duty water hose around the facility, hook it up and have a go at the doors. Good enough pressure to get the dirt off and not take off the paint. Our doors are about 11 years old and in good condition so we don't have too much of a problem here in Rancho because the Santa Ana winds take most of the dirt away.