http://www.pickofthelitterdogtraining.com/GentleLeader.jpg
I found this link to a pic. I got it since dash tries to eat other dogs that approach on leash, but overall it gives more control. I had a dog trainer fit it on him since the fit is rather tight, so it does not slip unlike the Halti.
Actual training would be best, but this could give you more control in the mean time.
Thank you for the link