Definitely keep exposing your horse to the ropes. You could lay ropes out on the ground and "send" o lead him over them like ground poles. I would lay a rope across the threshold of his stall or pasture (or any other place he likes to be), so he gets an instant reward when he goes over it. You could let a rope drag the ground when you lead him, but be sure that you and your horse can't get tangled up at all. Find a buddy to drag a rope in front of your horse and let him follow it. Allowing him to "chase" the "snake" is a major confidence builder. Anything that involves rope and is safe.
A stubborn horse walks behind you, an impatient one in front of you, but a noble companion walks beside you ~ Unknown