its a grey area , taking back an Ex .
i never do it ,i know a few times they might be good as gold from then on, but i dont take chances and would rather find a new un
When a customer comes back you have them in a unique position, you can usually tell them straight that you won't be messed around without appearing pushy or aggressive.
Try telling a new customer that if her husband says he is going to clean the windows himself she needs to tell him to p off, they ain't going to swallow that.
New customers are a pain. You have find them then quote them, then its the first clean, explaining WFP, then they too might be a messer. No point in turning away someone who you have already spent all that time and effort on.