Twins have a ton of lift on the ass end with so much prop. The right turn is because the back end is prop walking to the left. Brad mentioned the 45 degree angle leading edge fin. This causes lift in the turn fin to help push the front end to the left. Same can be apllied by pushing the bottom of the fin forward to create more lift. The toe in on sponson does the same by running your turn fin to the left. Band aids the problem imho. I would try to work on the problem first then use the band aids to dial it in. A deeper rudder will help to stop the walk. Wider too. I run lead in the bait box to plant the rear end more. Also removing lift by running struts flat or slight negative angle helps as well. Glenn mention sharp props. As the prop enters the water the profile of props will cause lift. The sharper it is the less lift created.
Good luck
Mike