At wit's end with potty training, any help?

We've been following the "oh crap" potty training book to try to help potty train a 2.5 year old. It basically consists of blocks, where the first block is nude potty training, second is commando, and third is underwear.He is basically 100% potty trained in block 1 (nude) and 0% potty trained in block 2 (commando). Nude, he will do everything, go on his own without prompt, and clean and wash up. We've been at block 2 for 3 weeks now, and he just does not get it. When he pee's in his shorts, their is no recognition, no stopping playing, and no notification to us. Often times, he will start to pee, and I will grab him and put him on or near the potty. He will resist this with a typical toddler tantrum. So he gets a change of shorts, and often will immediately pee in the new shorts. There have been days that we have gone through 10 pairs of shorts before lunch.We have also tried some modifications including going straight to underwear, using treats, and using a timer, all with 0 success. One thing that I think he may have trouble with is that he cannot pull his pants on and off without help, so I wonder if this has something to do with the resistance to using the potty when dressed, and 0 resistance when nude.So I am pleading for any help or shared experiences when it comes to potty training. Has anyone gone through anything like this before and could share some tips? via /r/Parenting http://ift.tt/2uilT1Q