On my pressure washer the container that you put the soap in connects to the spray wand. The soap does not go thru the pump.

Do you know of a pressure washing company that uses simply green? Thank you

I only use water. Nothing else. No chemicals at all. Does a great job.

Mine, you change the tip, and this causes the cleaning solution to then go to the wand, and it carries a very clear warning about what you use for a cleaning solution, so it appears different power washers have different ways to do this.

Same here........
We have a white metal pergola and once a year I power wash the green mildew with plan water, try that first.
My wife has got lots of flowers around our house, so no chemicals for me.