Well, maybe you could try "extended pauses" for up to 5 seconds to completely eliminate momentum. Plus, it should help you to better control the eccentric contraction, because you won't be tempted to bring the weight down so quickly to do a touch and go, at least I would think so in this case. Also, if you do decide to give the extended pauses a try, be sure at stay real tight during the pause and don't let the muscles relaw while the bar is on your chest.