Keyboard shortcut for brush rotation

[kmkenpo]

I am sorry if this is something that I should be able to easily find on the net... but each and every tutorial / help page, gives basically the same answer... but it simply does not work.

How do I bind AND use then activate a keyboard (or mouse wheel) shortcut that allows me to rotate a custom brush so that I do not have to constantly go back and forth with a slider to make micro-adjustments?

Thank you for any assistance.