Richard-
You won't be successful (IMO) until you find a way to reliably empty your pouch. I'd keep looking until I found a doctor that could figure this out, even if I had to go to Cleveland to do it.
In the meantime, you could discuss with your doctor alternate emptying methods. A tap water enema might be sufficient, but if you can't get your sphincter to open (or corrdinate with the rest of you), then an irrigation catheter might do the trick until you've worked out a definitive solution. Some people have irrigated their pouch for years, but I'd only recommend that if no other reasonable solution is possible.
Straining may be making your problem worse, by closing things up when you push. It sure as heck isn't helping. Good luck!