cleaning ludisia discolor leaves

[NEO Newbie]

I use a soft paintbrush to remove the dust that collects on the leaves of my ludisia discolor, but would LOVE to rinse it at the sink. I've heard water on their leaves causes a permanent white mark. Is this true? (I could experiment by washing ONE leaf to see what happens, but don't want to sacrifice a leaf to my own ignorance.) Hoping this is just an old wives tale.