Well I hate to say it but you may have to wait it out until he grows out of it. I've tried the pinapple and know others who have and it had no effect what so ever. I even tried the forbit and nasty habit pills that you give them. Some will just keep on doing it for a while.
you can give it a shot with the recommendations out there but know that it may be a way befoie he stops doing it, if he ever stops....I really hope mine stops soon
I do have to say that as mine has gotten older it has become a less frequent occurence. thank goodness!
it was pretty bad around 14 weeks but now around 21 she seems to be getting less and less interested.