How to treat eye staining on white dog?

Hi, I have a white Havanese/bolognese mix, and his eyes are always leaking, and he has brown stains. His mouth is also stained. He recently had a small white lump removed from his eyelid (we still don't know exactly what it was) and I thought this would help with his eye stains, but it has not. I clean the area with Crystal Eye tear stain remover, but with no results. Does anyone have any suggestions to remove the stains? thanks

No experience with this, but I've heard that it can be related to diet?
What do you feed him?

Sorry BlueJay but you're wrong about eye staining being due to diet. It's due to the shape of the eyes which in breeds like Tibetan Spaniels, Pekingese, Bolognese etc are round and slightly protruding.

I use a product called CleanOccular to remove stains from the white fur around Chloe's eyes. I can't say it works too well but I've yet to find anything better.

I agree with it not being totally diet related but some foods will make 'beards and moustaches' worse. Both of my dogs have white beards ... one has staining the other doesn't so it is also to do with the type of hair. My dog that doesn't stain has coarser hair than the other.

My breeder (when he shows dogs) used bicarbonate of soda but that is on beards and not near eyes.

The worse food for staining was James Wellbeloved!