This is not anything you can train a child to do. It just isn't. Stop with the wet beds, the waking up to go pee, and the alarms.
We did all of that and there is no point. All you are doing is what we did - depriving him of a good night's sleep, spending money on alarms that (by definition) only work when he's already wet, and increasing the laundry. So if it's a physical thing and there is no shaming involved, why is your husband so insistent on taking away the equipment your son needs (Pull-ups or equivalent)??? This is entirely developmental. Would you take away food because your child wasn't able to feed himself? Would you prevent a child from crawling because you thought he was old enough to walk? Would you fail to respond to crying or gestures because you thought your child should be old enough to talk? These things are all developmental milestones and nothing that you can force or teach. And I think thinks are going to get a lot worse because your child is unable to get uninterrupted sleep because someone is rousing him to go pee or he is waking up wet many times. He absolutely must sleep.
I'm not a big believer in medication, but I can tell you that we were thrilled when our pediatrician referred us to a pediatric urologist. He was great, told us he had kids (mostly boys) of all ages, up to age 18, with this problem. At no time did he mention anything about vasopressin. After discussion, we decided to put our son, at age 7, on a standard low dose of DDAVP. One pill at night, and he slept all night and was dry every night, no exceptions (after the first few days - I think it took a few days to kick in). Our child was able to go to sleepovers and, later, to overnight camp. He was still wetting the bed at age 10 when he went off the medication, so he went back on until 11 or 12. That's when his body was ready. I'm not saying to do that. But if you don't, you have to put him back on Good Nights or other product. Please go see a urologist so you have another opinion. Constantly limiting fluids isn't going to help much. And another alarm, after you've already spent this money, is still only going to tell you when he's already wet. Plus your kid is afraid of it and it's going to wind up shaming him whether you intend that or not.