This is a confession of sorts. When I started training Sanji I took an 30-day online-training course for puppies which was quite useful in many ways for the first 6 months to teach us not merely how to train him, but how to care for a puppy (potting training, crate training, schedules, toys, etc.). It's "positive-reinforcement" conditioning. The trainer doesn't recommend e-collars, synch leashes, electric fences, etc.
That was all well and good until Sanji's prey-drive kicked in around 6 months as he entered puberty. At 4 months his recall was better than at 6 months. He didn't respond to treats in high-distraction situations so positive reinforcement conditioning couldn't be continued. It probably could be with a non-hound breed. Not a basenji.
A side note on treats, I subsequently discovered a high-value treat that he will respond to for heel conditioning .
I get fresh salmon filet, remove the skin, then cut the skin and flesh into small cubes or pieces, dry in oven on low heat for half a day. Store in fridge. It's all I use now when I do heel work and it makes positive conditioning progress possible.
When I hit the training wall at six months, I realized I had to start using an e-collar. But after a month or so, I also realized I wasn't using it as effectively as I could be. For example, I was escalating too gradually from vibration, to sound, to low stimulation to high stimulation. The timing was off.
So I talked to a friend who hunts birds and has owned Vizlas for years for that. He recommended a better collar to start (dogtra) and said after teaching the ABC's, he sends his for board and train for two months. I found a local, show-award winning, black lab hunting dog trainer. Just one private lesson so far, but learned how precisely to use an ecollar, and its really help a lot. The first time I say "Sanji come" its a "freebie." The second time is not and he is stimulated. The level has to be adjust just enough so that he does respond. As she put it to me, "you want your dog to know that when you give the recall demand, you mean it."
Wish I had known this at 6 months. More recently, I explained the problem of Sanji bolting away after something and not responding to the ecollar in our local park (City Forest), which is 520 acres, and running well out of my sight, leaving me standing there not able to use the ecollar since he's out of sight (have to see his response or lack thereof to use the ecollar). I had to stand there and whistle and call his name for 5-10 min until he returns (and fortunately the extensive off-leash training so far has helped since he has returned every time so far. But I could see this wasn't working and she confirmed what in hindsight what should have been obvious: discontinue biking with him at that park and just stick to the smaller park near my house (24.9 acres and fenced), where I can see him almost all the time and he can't get lost, until we get the recall and "stay near me" whistle training down pat. I suspect that'll be another 6-months or 1 year or so.
My takeaways:
(1) an e-collar is an essential tool for training a basenji to recall in all situations, including when he bolts after prey or other dogs
(2) an ecollar is useless unless you can see the dog's reaction (or failure to react, which requires upping the stimulation) and the timing between the command and stimulation is crucial
(3) whatever this kind of training this called, it's effective.