Let people dump their gold into some cosmetics. Make off-season items available for some gold for example (1 mil for a christmas hat or pumpkin head etc). If you make something ridiculously expensive the people with money to burn with pay for it, especially if they can show it off in game. Basically we need TF2 hats
That and let people dump their gold into some titles that get announced when they join the server like for the people who own fiefs, or let people skip the respec timer. Stuff like that.
Don't just delete gold. That undermines the progression which is half of what makes some players come back and stay invested in their character