She really has to be the responsible party here, Need thinks, though she does rather think being rattled would be good for Hanako. "I'd advise you to take it off to dip it. All the water here is the River, so being fully submerged is pretty unpleasant. If you want to find out, I'd advise you do it when other people are around."

Being the responsible one doesn't mean she has to spell out what flavor of unpleasant it is unasked. Also, she's not sure it's any different from what the River was like in the Desert. She'd never fallen into it there.