Few weeks ago, I canvassed existing window cleaning customers on a 'poah estate' I spent an hour (if that) canvasing, and 3 hours doing the work the following day.
Turned over more than £30 per hour.
Was well worth it, but I feel that its in your head, which customers will say YES. out of the custys I spoke to, I was only turned away,by 2 of them.