@Kipawa:
Prong collars. Oh dear. I'm not a fan of them. When I see someone walking a dog that wears a prong collar, all I think about is whether the owner is substituting a prong collar for well directed training. However, in training police dogs, maybe it's a good choice? I just don't know.
I think prong collars can be a useful tool with a large dog that doesn't listen. I believe they are a better option than a choke collar, as they are a "martingale" style, and the prongs should be an automatic correction. Unfortunately, a lot of dogs learn to ignore the discomfort and lean on the collar anyway, if the handler does not use it correctly.
Basenjis certainly will ignore discomfort and pull, especially if they see something that excites them. Yes, you can sort this with various methods, target training, etc. but many will revert when excited. I like a wide "hound collar" for control without much risk of injury, since with the width of the collar the pressure is well spread out. In some situations you just have to make the dog behave, and I refuse to allow my boy to lean on the collar, so it is pull and release until he figures it out. (A slack leash will allow you forward motion, a taut one will not, and may indeed result in a backwards retreat from whatever is attractive to you!) I think flex leashes are a terrible invention, as they teach the dog to pull! A dog aggressive dog on a walk can be challenging to deal with when other dogs are encountered, and you do have to be able to control him. At least Basenjis are small! (I would hate to have to deal with 100 pounds of Basenji "attitude"!)