I had an older Sears electric power washer that had the wonderful feature that it would apply detergent at high pressure, rather than the low pressure detergent application that seems more common. It was very effective despite being lower pressure and lower volume than many machines. I prefer it to my 4gpm 3,000psi machine that is admittedly more powerful at washing off dried cracked on gunk, but not as good at getting things "clean".
Any thoughts on a favorite equipment wash/detergent?
All the best,
Peter