You will have tons of problems trying to get those stains off oak. Any moisture left on oak turns it into a greeenish , grayish stain. About the only way to get rid of the stain is to sand the wood. It may go so deep that the board will be dished out with all the sanding. The bed must not have had a good topcoat of urethane on it to stain in the first place. Somebody above said it may have had only an oil finish on it, maybe that is the case. But I would bet that you have moisture stains that only can be sanded out.
