I think the original question was about vinyl windows. Definitely don’t use abrasive tools or cleaners with that! For vinyl windows, I only follow the manufacturers recommendations and if that doesn’t clean it, I’m not gonna use anything special without the customer signing a waiver and up charging.

A good mileage app will pay for itself in a heartbeat if you’re using a personal vehicle. Also, technically, even for a work truck my CPA recommended that I track every trip. If you ever were audited by the IRS, they may ask for these details. There are devices out there that you can install in your work truck that will automatically track every trip for you so you don’t have to mess with that.

I’ve never tried an Xjet for roof washing but sounds interesting. If you use straight 12% SH with the Xjet, I would think this would work. There are videos online with people doing it. You should get a 3-1 mix with an 8 gpm machine without any proportioners which gives you 4% SH. You might have to go over some spots twice if that’s not hot enough but I usually start at 4% for most roofs. Also, you can use an Xjet with a lower GPM machine and get an even hotter mix. You’ll just need to make sure you use a separate water hose for spraying down the plants, etc. And most importantly, don’t take my advice with roof washing. Always test test test!