I have found that for me the hardest rep of a heavy deadlift set (say on a set of 3) is the first rep, not necessarily the last. Getting the weight started seems like the hardest task. If you just tap the weight on the ground and immediately go up with the next rep, you get a rythem going. If you set the weight down and take a quick breath and go back up, it's like lifting the first rep again.
By the way I can't imagine that this is cheating since I'm pretty sure a heavy bar doesn't bounce much. Just a tip I found.