Just keep putting it on him and he will get used to it. I would cut the size of the insert down so that it isn't hanging out. The poop lands in the pocket anyway. If he can handle it for an hour, take it off if he is still pulling at it and try it again in a while. Bob now sits in front of me and waits for me to fasten the tail clip! Getting it off while Bob is trying to wiggle is the real challenge. I slowly "peak" in the pocket to make sure none of the goodies have fallen out in the process
I am feeding him clovers every time I put it on him.
I'll send pics to all of you in one second.
My camera isn't working so I have to fix that first...