Pressure washing can earn great money, but the kit starting out can be costly.
You'll need a 13HP, 4gpm machine to run a flat surface cleaner properly. The best way I've found to have it setup is with the washer in the van and 200' of hose. Dragging the machine, barrel, etc in and out of the van & around houses is hard work,.. those big machines are heavy!
I use a lance for cleaning gutters. Its much quicker than WFP,.. but on occasion I still find I have to pre spray with TFR to get good results. The extendible lances are heavy too until you discover the knack of using them!