I'm not quitting my day (night) job anytime soon

I have one well-trained dog who walks right next to me and sits when I stop. The other one attempts to choke herself into unconsciousness. Halti? Smalti. She just tightens her neck muscles and forges ahead. I've tried EVERYTHING I can think of.

Lately we've been all about positive reinforcement and behavior shaping, which works like magic on my younger puppy, Annie. But Banjo, the problem child, laughs. I mean she really laughs. She shakes her ears and yodels. I'm not making this up.

Today we got our new Starmark training collar and set off on a mission to teach Banjo "we aren't going anywhere until the leash is slack." She pulls, we stop. Annie grasped this immediately, and I'm pretty sure Banjo understands quite well what I expect. She just chooses not to do it. We spent 30 minutes going about a block and a half, and then we were both so frustrated I brought her home.

The neighbors are probably laughing again.