C'mon guys, it's not a dangerous weapon, just a high pressure cleaner.
Use it to wash anything you like, just don't get to close.
Hold the unit about 15 to 20 cm's from whatever your cleaning until your confident and all should be well.
Provided you keep your distance from seals, rubber hoses and electrical conectors your presure cleaner won't damage anything.
Water jets can also cut steel if the jet is thin enough, and the presure high enough.
Water Jet cutters
Ben.