Holy dripping saliva!!!!

I have posted before about issues with a dcb. He is 4 years old and has so many strange things going on. Last post was about his regressing on potty training and peeing constantly. That corrected itself overnight, we haven't had an accident (even at nap time for 2 weeks now). Now we are onto something new. The last few weeks he has been running around with his tongue out. He used to just do it at craft time, or whenever he was concentrating. But now it is constant, and slowly gotten worse. This week he has it hanging out down to his chin....all day long. and the spit that goes along with it has gotten worse too. Today it is dripping off of his chin. Poor guy has sores starting and he can't seem to help it. I constantly remind him that his tongue stays in his mouth. Today I gave him a clothe to wipe his face as I am tired of doing it for him. Mom says it's just a habit, and how can you break a habit....I don't know... I can put up with baby\teething drool, but this is gross. dripping all over and I honestly don't think he even notices. help...suggestions?

EW. :(
The only thing I can think of is CONSTANT reminders. "Tongue in your mouth, please", whenever necessary. Does he seem to be doing it conciously? What about coating around the mouth with vaseline? Or something that doesn't taste good, but won't harm the skin?

Not sure how to stop him from doing that other than constant reminders? In the meantime, I would ask mom to supply a supply of cloth bibs that he can wear throughout the day to at least catch some of the drool!

He doesn't seem to notice he does it. It was soooo bad today it was dripping onto the table during snack time. I am constantly telling him ":tongue belongs in the mouth", and "please wipe your chin". It makes me wonder that something is going on with him, the peeing his pants for the first 3 weeks back from vacation and now this. His chin has sores and his mom puts lavender oil on it. you would think that the taste of that would turn him off. At a loss. Thanks for the reply ladies!