I have the bathtub shelf now for some time in use. Although certainly the one time or another shampoo or shower gel has leaked on her and she will regularly wet by the showers, the wood has not changed or even moldy.
The distances between the individual rungs is closely enough to take even small things without any problems.
However, I would advise earlier to take a look at the length of the article, since this does not necessarily fit on each tray.