All that I have ever heard is that many boys need a bit longer to be interested in potty training - certainly true for the only boy in my family...
I don't know the book you are talking about, but honestly, it's potty training - not brain surgery...
My DD was potty trained when she was 2.5. It took about a week until we were accident free (a bit longer for nights).
Like you we had bought a potty long before to get her used to the idea. About 3 weeks before our target date (a long weekend, since I worked during the week and wanted to make sure I had the time) we started talking up the potty and how we were "running out of diapers" and when the diapers were gone she would be a big girl and go on the potty.
When the day came we put on undies and NEVER looked back. I didn't even keep any diapers around the house anymore. We were truly OUT.
I put her on the potty about every 30 minutes or so. We did not do nighttime diapers. First day I basically walked behind her with a mop (LOL) - lots of accidents, they happen, you clean them up. Easy. Second day: less accidents. Third day: no accidents, we started spacing out the potty trips to once an hour. The first week that followed we had a few accidents and a few days without any. No big deal. We spaced out potty trips to every two hours and before and after meals and trips.
We had a few nighttime accidents as well, again with double sheets and absorbent pads not a big deal.
We never offered diapers for pooping either, just M&M's as a reward and a healthy diet with lots of fiber and liquids to make it easy.
Accident frequency really dropped after two weeks and I declared her potty trained. Yep, it takes a bit of work and some extra laundry (we did it in the summer so running around in undies at home kept the laundry at bay).
Now that said my DD was READY, meaning she never refused to sit on the potty. If she had I would have not put up a fight about and maybe tried again in a few months.
My only nephew wasn't on board with the potty until he was almost 4. Put up a HUGE fight when my sis tried to get him to use the potty. Not the hill she was going to die on. Then one day he decided he was done with diapers (I am suspecting playground peer pressure) and never had an accident. He was just ready.
My advice: you know your kid. If he's ready and you don't mind the clean up give it a try. If it seems to be a struggle - don't. If your husband thinks is so important and MUST be done now, let HIM be the one doing the cleanup and die on that hill.
Good luck.