Negative Fees?

Anyone out there use fees in a way to apply a negative fee?  I know there is the check box Amt is Percentage and Allow Negative %, but it is a rule based fee, which I don't want it to be.

What I want is for a staff member to be able to apply a 10% discount off an order. We are looking into having layered price maps with fees in the layers, but as we transition, we want to be able to give patrons a small percentage refund if they complain about fees. 

I know about Discount. But any way to apply a negative fee that isn't a rule based fee?