If they are gritty I would suggest dunkin those babies in the garbage. Its not worth a main or your clutch bell, shoes and diff/spur gear when they go. Also I never had any luck with grease/oil on clutch bearings. It always seemed to be slung out onto clutch shoes cause slippage and self grenade real quick. I just take the new ones and blow compressed air to get the grease out. If oiling works for you rock on.