Hi C.,
I completely empathize with you. I'm a mom of 2 boys who are now 10 & 14. When my oldest was young, I swore that he was going to be in diapers at age 35. He had no interest in potty training and didn't care how dirty he was, it just didn't bother him. I tried every little thing I read about or was told, and finally at one of his pediatrician appointments I told the doctor I was at wits end. He promised the advice he gave me would work, and he was right...it was about 1-1/2 weeks after that, and we were well on the road to potty training. He explained that some boys are just not interested, and you have to make it more interesting for them. Here's what we did....
He told me to get an envelope and put a small 'surprise' inside the envelope such as a little car, small toy, money etc, seal the envelope and tape it to the wall above the toilet making sure it was high enough that my son couldn't possibly reach it. He advised me to use the same bathroom all the time, take my son to the bathroom and explain what we do in the toilet. (he actually did ok with urinating, the problem for him were bowel movements) Then explain to him that when he does his business correctly in the toilet, he will be able to have the envelope when he's finished and see what surprise is inside. (The doc told me that curiosity will win out, maybe not the first couple of times, but that he wouldn't be able to stand not knowing what was in the envelope at some point. ) For most of the first day, he would say he had to go, go to the toilet but wouldn't do his business, got up and wanted the envelope. As soon as he realized he had a job to do in order to see that surprise, he finally went in the toilet for the first time the next day. NOW one important part is that as soon as they earn that envelope, you must immediately put up another envelope with another surprise in it. After a couple of days, my son realized what he had to do to get that envelope, and then it got to the point when he was going well, that I had to limit the envelope to once a day because he was trying so hard to get those envelopes!! It was really cute, but most importantly, it saved my sanity!
Please give it a try, and I promise you will see some results if you keep at it. Please don't hesitate to drop me a note if you have any questions or problems. I'll certainly try to help. Hope you find this helpful, and GOOD LUCK!
P. D.