D.Z.
HI, one thing you might try is putting cherrios in the big toilet for him an tell him to see if he can hit them with his pee. I apologize I could not think of a really polite way to say that in any other form. My grandson is going to be 4 in oct. an I had told him to see if he could hit the man in the hole, well he did then we all had to play the game of that someone was going to beat him to the man in the hole. So needless to say it had to be him to win an luckily he would hit the potty everytime. Now back door that is gonna have to be when he is ready nothing works on that one believe me we tried them all until he decided on his own to do it. Best of luck to you.