Turn your pressure washer into a high output pump. Empty rain water from
construction sites, clean up chemical spills or remove slurry from a car wash
bay at an 11:1 ratio.
Also consider a foot valve. Foot-controlled valves allow both hands to be free resulting in better control. A few years back we were actually contacted by a large energy corporation needing training AFTER a work-site accident in which a sewer nozzle cut through an employee's boot, skin and down to the bone. A foot valve was installed after-the-fact to ensure that this accident would not be repeated. Don't wait until someone gets hurt to consider this tool.