can I make it so that the right mouse button can be used to reduce the number of uses?

I don't know if you can, but the first sentence isn't bad English.

You can do this by creating a procedure linked to the items "On Right Clicked In Air" and "On Right Clicked On Block" and make the following procedure.

Deal (Damage Number) Damage to Item in Main-Hand of Target Entity

You can find the deal damage to item in the Item Procedures Section and you can find Item in main hand of target entity in the Entity Data Section.