It is appealing isn't it? No hose, no ladders, no pure water, no parking problems...
The thing is, although I'm pretty good with a squeegy and do a minimal amount of detailing, I still have to use scrim depending on the window frame construction.
Do you really think you could do a good enough standard of work using a wagtail only for domestic 1st floor properties?
I think that would take some practice, if it's possible to do.