Hi

Have you tried telling him NO!?

Does he react to discipline? What do you do when he is naughty?

I would suggest that you look at the the bigger picture and the fact that he is disobaying you and deliberately doing something that you are telling him not to. If he was sticking his fingers in an electrical socket, running out the house into the road - what would you do??

Yes - I know it is not as serious and I know that he will not come to any harm BUT he is disobeying you and you should stop this from being an option for him. What will you do when he is older if he pleases himself now. It has probably become a bit of a game to him, he wont remember why he does it only that he gets a reaction from you. Discipline him in general and he will respect that what you say goes - and NO he is not to young for time outs.

Hope you can turn this around.