Hi all, I made my first post on this thread in haste as I was going out so it was probably a bit misleading. I was referring to first cleans on either new properties or newly fitted double glazing where stickers or labels have been removed and left that annoying square mark in the corner of each window but the windows are otherwise reasonably clear of debris. These marks don't wash off with pure water or even something like viro-sol. At ground level they can be cleaned off by hand with soapy water and a scraper but upper windows were what I was enquiring about. I use ladders if I have to at the moment for the first clean then switch to wfp. But I was wondering if anyone has found a way to remove these marks with wfp? I should probably have started another thread. Apologies