Refunds generated by charitable donations documented on tax returns have always been a source of disagreement between believers. The churches I attended growing up were so determined to do their giving on the sly that they practiced something informally referred to as the “brethren handshake”, in which a little envelope full of cash was passed from hand to hand under cover of the traditional greeting.
It wasn’t as hard to detect as they thought, but you have to give them points for trying.