Jeannette - a power washer would work very well
Just use your garden hose and a brush with dish soap. If you don't have a garden hose because you live in an apartment, put down a plastic Dollar Store shower curtain and hand wash with a bucket of water soap and a sponge.
If they fit, you can run them through the short cycle of the dishwasher, if not just repeat step two until clean
Wipe down with dish soap and hose down with your spray nozzle set on Jet