John never taught Dean what he really needed to know to survive the torture in hell. He treated them like soldiers- but not to the extent he was trained. He was trained not to give out secrets under torture conditions, even if it wasn’t as intense as some fields or positions give him. But as strict as he was, and as much as he could do, he couldn’t put his kids through that training. They were kids, after all, and it was bad enough he had to train them to do what he did.
But he did train them on other things, that could be hard to do. How to escape being tied up- if possible, how to effectively tie other’s up, quick use of handcuffs, etc, etc. While he might play as if he wasn’t paying attention so they wouldn’t try to slack off and get him to help, he was always in the same room, and always pestered by the other brother- even silently- to interfere if it went on for too long. And he always rewarded them with ice cream or something if they managed to do so.
The worse was teaching Sam to escape from car trunks. He taught Dean, but it was more formality, where Sam was at more of a threat, and much more needed to be known. After all, the kid was being hunted by hunters, and the people dead because of him, and the shrtiga, and the science teacher demon thing that tried to take him, and then he talked to strangers in cars following that? The kid was a special level of optimist. The first time he hovered by the car trunk, telling him what to do, especially since the kid wasn’t even ten- with Dean insisting they let him out after only a minute or so. But after several times when Sam managed to escape on his own, the kid was so damn proud of himself, he forgot to ask why he had to learn it that time. :]