Hi Paul,
if its the big Asda Walmart at Cribbs Causway you're talking about, well I was in there a few months ago and the guys they had window cleaning looked like a right old motley crue!
No pouches, scrims, applicators or squeegees. They had SPONGES! with water so soapey they must've emptied about 5 bottles of fairy into it!
One was working while about 4 others stood around their battered old van smoking and looking grim.
After having that lot, I bet if you just turn up and look halfway professional, they wont mind what you charge!
Silly