never do a recall off lead until your dog knows it well, reason being [for any command] once they know they dont' have to listen, you are in trouble. teach him everything with the lead on him, use treats to get him to want to do it. like for instance, when i did come with bear.. actually okay i did it off lead, but like we would be at the park, and i would start to run, dog will follow, then yell COME.. and keep running [backwards so you can watch him coming] and eventually he will catch up and GOOD BOY> TREAT. i dont' know if all dogs will follow if you run, i have shephards and they tend to want to be near you.. so it works like a charm.
and as for the choke chain, YUP, they stink.. most people do not realize not to use them because they can certainly harm a dog because of what you said, they just keep pulling and pulling and choke themselves..
personally i have to use a prong, and its more humane than a choke. i have never used a gentle leader, but i should probably try one. i wonder if it would work on bear.. he's so darn strong tho.