How do you do the windows with the vents? I'm about to switch to WFP and one of my (excellent, monthly (most of mine are 6 week), well-paying) customers has vents, she switched to me after her previous WFPer used to drench the vents which obviously dripped and splashed her windows afterwards. It's a big house so I'm keen to not have to use the ladders! It'll be so much quicker with the pole.