Is there a cure for white hairy tongue? had this for years?

Has your dentist,ENT specialist or oral surgeon confirmed the diagnosis or recommended treatment for it through the years? I can't think there's a fungal infection or serious disorder after all these years. Are you symptomatic from it? Consider a second opinion at a department of oral surgery at a dental school near you.

Oral hygiene: no smoking, fluoride toothpaste + soft bristle brush & brush tongue. Listerine to kill germs & zinc 50mg per day for tissue health. Vitamin A foods: liver, eggs, leafy greens & yellow fruits & veg, like sweet pot. Squash, carrots. If persists your doctor can work with pharmacist to compound a special mouthwash.

Yes. See your Dentist.