I doubt a liquid bandage is like GIAB. It won't take over a month to see an improvement, it only takes 3-4 to see new skin when GIAB is applied.
I don't think the white line has anything to do with candida. I think it's just dead skin that gets into contact with your saliva or when it gets detached from your lips when overstretching, so it turns white. I managed to heal most of the white line by applying GIAB directly onto that area for just 5 days.