I want to get the mildew off my house. I've got a 1800psi electric 1.6 gpm Clean Force pressure washer. I bought a wand extension w/ 1/4" QCs. The eve's are 19' up. But I'm going crazy trying to find a chemical injector. I don't know if I want downstream/low pressure or a high pressure foam cannon. I don't need high pressure...it's painted treated pine siding. The handle takes a male M22 wand (the other end is a 1/4" QC). The hose end of the handle also has a male M22 connector. Please help me...thanks!!!