Teachng in hand manners

[Vodkagirly]

I'm currently sharing a 16,2 ISH with a neck like a rhino. He is a fine to lead untill he sees another person and then will drag me over to see them and won't leave them till he has checked he isn't getting treats, its getting ridiculous and its a bit like a thelwell picture with the greedy pony just dragging the owner around.
Obviously no one is now giving him treats but its obviously learnt behavour which I need to get him out of. To make matters worse, I have a broken wrist so can only lead with one hand.
Need some sugestions of what to do as what has worked with previous horses is having no effect on him.

 

[ginadrummond]

I've got a black cob similar and I use a chifney when he starts dragging me. He needs reminded every couple of months or so. Its probably a bit severe so any of the controller headcollars (monty roberts etc) will work for most horses but not mine alas!

 

[spaniel]

Bridle, schooling whip, determination.