Since people keep asking if it is possible, the answer is no, unless the waived player is signed to a minimum contract. Just like in baseball, the team that claims a player off waivers assumes that player's contract. Unlike baseball, there is a salary cap in the NBA, so the team would have to have salary cap space or an exception like the traded player exception in order to claim someone off of waivers.
Bonus info: the Celtics cannot get a disabled player exception for Jermaine O'Neal or Chris Wilcox and, if they could, it wouldn't apply until next season. Since neither player is under contract next year, there is no way the NBA would grant such an exception, even if that player died.