I have two Golden Retrievers and walk them together. The !$@%%, Josie, is fine as we had a dog trainer for her ( who also used then sharp turning round method) and she was a quick learner needing only one hour lesson. However the much larger dog, Colin, is a bit thick and hasn't responded to the same method (can't afford trainer now). He doesn't really pull but walks too fast, he stops if I tug or call  but then sets off at the same pace. So I'm going to try Terrie's 'lead between the front leg' suggestion or if  that doesn't work then the Halti.
What a useful thread!
Cassie xx