i tell them with a smile: even when is raining i still need to feed my kids 
always work! 
I never use that, although i can see it might work. Lol
I'm not a charity, and so don't expect the customers to care about my finances.
It would be like turning up and saying.....
"I know I didn't clean your windows missus, but can I have the £10 anyway? My bills are due"

The same as above, I offer 24 hour guarantee. Not one call back yet.