NO - the seesaw method is the absolute WORST way to teach a horse to frame up, because it hardens the mouth and creates a false frame. You have no access to the back and the horse falls on the forehand.
cant agree more
it is important to remember when working a horse long and low not to focus on just getting its head down!!the back must also be rounded and his hind working well underneath him,otherwise the head carrige will be unsteady and he will be working in 2 a 'flat' frame, giving a short stiff feeling through this back rather than a elevated one thats slightly extended with bounce.if the back is rounded and hind legs under he should be quite willing to take the contact down whenever offered.for a little more incouragement you can widen your hands and lower them slightly,though shouldnt be neccasery.if hes still struggling you might find it easier to ask starting on a circle where he will be more 'together' anyway and work him to the outside rein,then you can make little flexions to the inside keeping the outside rein still,and on the 'give' give a little more than you normally would even taking the rein forward so its slighty loose so he has 'room' to strectch.use plenty of incouragement with your legs to keep him going forward into it,and concentrate on keeping his back round and working.doing it at the end of a schooling session to start with may help.
collection however involves raising the head and frame and working in a streched long and low way should be establised first.