Yu can do it, but only if you plan on playing only the very best premium hands. As in AA KK QQ, AK Suited, MAYBE AK off suit, and JJ. But nothing less than that. Also, unless your blind is good, just throw that away too, that way you won't get trapped.
Guys roll into those things with a grand or two intheir pockets and just don't care. So just sit and wait. If you lose with one of those hands then Oh Well try again.
But if their is an add on or something like that at the end of the hour, then I would take that. If not just sit, or get to just below whatever chip count you need to be below to re-buy. Just watch the clock.
I know guys that buy into those formatted tournies and don't even play during the re buy time, they just blind off, then sit in after there are no more rebuyus.