Saliva alone won't cure this, man. I stopped using only saliva because it didn't really do anything to my bottom lip. I'm only using a little saliva now but I constantly apply Aquaphor on them and my lips feel great and elastic. My upper lip is doing great though. The redness has reduced and lips have a better color. I've started this on Monday, so I'll wait another 3 weeks to see if there's any big improvement.
If you don't have Aquaphor you can use another lip balm and apply it after you licked your lips to seal in the moisture. You gotta apply a couple times a day. Make sure the lips don't dry out.
I think the skin cells are dehydrated that's why they keep dying. Keeping the lips moisturized at all times is probably the best way to improve this condition.
If I manage to cure this, then I'll let y'all know.