what I did with mine is boil it for about 5-10 minutes and then soak it in a bleach solution for about 2 hours.
I think I had about 1-2cups of bleach in a bucket of water. 50-50 would probably be too strong.
Actually, now, if I let my wood dry, it looks completely white!! maybe I bleached it too long. Looks fine when wet though.
I heard too that boiling the wood helps getting rid of the yucky color in the water and helps make it sink. I still haven't tried boiling it again though (too hot and humid aroud here!)
Anyways, hopefully someone who knows more than me will answer as well... I'm a beginner as well, so I'm not 100% sure of anything right now.