Of course, this can only works if all players, including the DM, are elves, dwarves, or gnomes *for real*. Because, by the time the third character gets his 10th bonus feat, 300 years will have passed in real time.
Unless you've got a DM that behaves like a cornucopia when it comes to XPs. Things like 5000 XP for offing a goblin who've stolen the inkeeper's son's lunch. In that case, don't bother with this meager martingale, and directly asks the DM to give feats freely. Such a monty haul DM will probably accept. "I've killed a goblin, so I should have learned Great Cleave from the experience." Try it.