Well to be honest I have never really smelled it after soaking it. I didn't really have many choices though as my tank was infested with mites and the pieces were too big for the oven. I always scrub first anyway to try to get any dirt off. You could even go so far as to add dechlorinator to the pure water soak...that should take care of anything that is left over. Not that I would really recommend bleaching if you have other options, but if you have to bleach the plant, I think doing the wood would be ok if it is attached. No personal experience though, so I'm not doubting you. It would make sense if the bleach doesn't even do anything because of the organic material.