originally used the yellow dirt worker – finally died on me last year after several years of abuse and plenty of replacement parts
now use a Nomad with twin batteries, a lot more useful than the plug in dirtworker -and loads of spares and accessories available on their website now (rather than ebay) – its a much improved and developed product now
cons – expensive and watch out for the flimsy plastic fittings at the base of the gun, they break easy if you drop the gun on hard paving = means you don’t get a good seal when connecting the hose and half the water sprays in your face and not the bike (£20 replacement cost for a new spray gun….. ouch)