Join Date: Apr 2008
Location: Alberta, Canada
I've taught many a horses to ground drive just using a halter and two lunge lines, and running them through the stirrups. The trick is knowing what hand to use and when and how to use it, and getting coordinated with all those lines.
When he starts to turn back, you'll have to shorten your line opposite of whatever way he is turning to straighten him back out, but not enough to make him think you're asking him to turn all the way around. You're simply blocking him from turning back towards you.
For example, if he starts to turn left towards you, you're going to pick up your right rein and straighten him out. If he over corrects and tries to go right, pick up your left line.
If he knows how to lunge he should figure out that your "clicking", or whatever cue you use for walk, means to just walk. Stay far enough back he can see you, but not too far back that you have too much slack in the lines so he gets caught up in them.
One thing I absolutely reccomend is making sure he is fine with lines flapping around under his legs (sounds like he is) so when one touches him in an odd place, he doesn't freak out and bolt.
Also be very aware of how your carrying your line - don't leave it dragging behind you or in large enough loops that you could get your foot stuck in one. IF your horse bolts and that line is behind or around you, you're going to go for one very unpleasent ride.
It's a lot of practice for both horse and rider but you'll both get it. :)
This is one of them "practice makes perfect" things, but if you've got someone who knows what they're doing to help, it'll make things that much easier.