I love watching cleaners trying to clean glass doors because the company's will not pay a window cleaner, our shopping centre the lad or lass starts on the entrance when I arrive I go in and clean 4 shops and doors come back out and they are still cleaning the entrance
I have seen them use all manner of chemicals and cloths and they never do it right, I was impressed one day when they were using mop and squeegies but they still made a mess
occasionally I clean a panel on the way out to annoy the lad