User blog comment:Akali95/Do Devil Fruit users smell?/@comment-4754162-20120517145747/@comment-4605926-20120517151630

SEA water without a slight doubt whatsoever.

As for your comment, I highly doubt that Jack and his crew don't do showers for this reason though. And yea, you're right, water weakens them but it's not like they can't do anything about it if it's not all over them.