Well, I thought dh was doing better.
I know it's a little on the passive aggressive side but (is that ALways a bad way to handle things) you could take the receipt and tack it to the fridge. Just letting him know you found it and you are NOT being fooled. Don't say anything. And if he removes it and throws it away, don't say anything. I think the point will be taken.
Might be a bad idea but....
Well, I was going to take Lucky's suggestion.