I swear by Proviable Forte (not the DC version) that's available only from vets. I didn't think Gilligan had stomach issues, but apparently he did. The vet tech, after seeing his horrible tear stains, said people had reported after giving Proviable for stomach issues tear stains disappeared.
They were right. After about 4-5 weeks of giving it to him, the tear stains went away and have not come back. He only has normal tearing now that washes off.
After giving it some thought, he obviously did have a "bad" stomach. When we brought him home he had giardia and was treated once. It was spring, and he kept eating those yellow oak flowers that hang from the trees. After each one he would just lie there and I would hear his stomach gurgling until I realize this happened after he ate one. Then he was neutered and got antibiotics.
So his stomach was never right... until Proviable. A bonus was that he stopped being so fussy and started eating much better. He now asks for his dinner, when before he would just snort at it.
It's on the pricey side, but I don't care. His tear stains were really terrible, and so bad I called his breeder to ask about it and was told his dogs generally don't get tear stains.