I would try the big toilet seat thing. my boys never liked the potty's. I had an opposite problem to you though my eldest especially hated pooing in the toilet so would go in his pants in the end I said he either pooed in the toilet or in a nappy so we went back to nappies for poo's. when he needed to go he would come tell me..

I guess if you have time you could sit him on the toilet just before his day nap and turn it into story time and tell him to do #2 while you read to him..