I'm doing that right now.
Keep in mind it might take some time to get all those tannins out. It depends on the wood. I've been soaking a piece of native ebony for about a month and a half in a 5gal bucket and it's still giving me "tea" :-/ I check on it about every 3 days and replace the water. It's some VERY dark wood, so your results may differ, and it also depends on where you got your driftwood from. If it had been crusing around in the water for a while, mother nature has already done most of the work for you!
Just sit that sucker in a bucket for a week and you'll probably be able to tell if it'll cause a problem.
Most fish aren't bothered by the tannins. In the wild, there're swimming with them every day.
You'll also have to boil it a bit to help things along and kill anything nasty in the wood. I just boiled some water on the stove and dumped it in.