How to Break a Bad Habit of Sticking Fingers in Their Mouth?

I am studying to be a Behavioral Analyst... and I have a 6 year old who constantly sucks on his lower lip. The problem with his sucking is if he does it long enough it gets swollen.

The most effective way that I have seen in my studies as well as with my son is constant positive reinforcement. I will try to explain without writing a book and explaining the psychology behind it. It is a bit of work but its worth it.

With my son I began making a statement like "Huney, its time for you to stop sucking your lip. Your a big boy and your lip is getting swollen and...(insert negative effects here)So I tell you what, let's work on stop sucking you lip and everytime I catch you without it in you mouth you get a prize".

Then everytime he didn't have his lip in his mouth he got a small prize-a penny. And I made a BIG deal out of it... Im talking dancing, singing, doing the Big Boy Boogie.. the whole 9.
-A trick is to reinforce her at times when she couldn't possibly suck her fingers to get her desiring the reinforcement and performing your desired results ie: when she is writing, eating, coloring, etc. The fact is she ISN'T sucking them! You know she couldn't.. but all she knows is that she did it!! Remember that we are concentrating on the desired result... not the
-Ensure the prize is small enough to be given out constantly but big enough that they want it. (pennies in a clear jar, m&ms, skittles, golden stars stickers etc.)
-You will have to do this constantly with CONSISTENCY for the first day or two.. decrease the timing of reinforcement after day 3 or 4.. etc. by a week or two she should be completly "trained" out of it.

The only downside to this is you will either need to be a stay at home mom or have a care taker who will reinforce this with you for the first few days.

I know it sounds like alot of work but if (and i dont suggest this for something so small) you chose to take her to a professional, they would use a similar process.. save yourself some money :)

Try putting bandaids on the fingers she puts in her mouth---especially the fabric kind. They don't taste good and they don't let them get very good suction (if she's sucking her fingers and not just putting them in her mouth). Had a 2nd grader in my class once that sucked his thumb and it helped wean him off fairly quickly!

I know how difficult this is to stop. I used to have a daycare home and it was a constant problem.
Here's a few things to try.
Make her keep her hands in her pockets.
Have her sit on her hands.
Don't say anything more about because it's not working and try to give her something else to do, color, paint, project when she is done praise her big time on how happy you are that she didn't put her hands in her mouth.
Then there was this stuff called, "STOP" to get thumb suckers to stop but that was when my daughter was 2 so that was 18 years ago but it tastes real bad but of course is safe. You could brush it on her fingers.
That's really all I can think of.
Lonie

If she's like my son, she may be doing it to focus or calm herself rather than out of habit. I've found the best way to deal with that is to re-focus him on something he can put in his mouth (a lollipop, gum, etc) or try to help him work through whatever has him out of sorts and needing to strongly focus/calm down. Lately, a gentle reminder to remove his fingers from his mouth usually does the trick, if not, I try to figure out where the stress lies.