Can anyone recommend equipment to increase grappling damage (not so interested in attack rolls it's already high). I have a wrestler concept and besides Crushing Grab I'm hoping some equipment exists to increase the damage when an opponent is grabbed.
I can't think of any off-hand that add damage to grapple directly. Crushing Grab is itself a bit of an outlier in that regard already.
Maybe something along the lines of elixirs or potions that cause you to have an effect that damages creatures that end their turn adjacent to you. You could force them to stay adjacent to you by grabbing them.
Grappling is for creating a condition for you and your teammates to benefit of, Not to Deal damage
There are a few spells that say an enemy gets damage when they grapple *you* which might work with some gms
But all you can do besides crushing Grab is to make the most out of the tactical use of grapple and it's follow up maneuvers