Voadam
Legend
werk said:I would allow it to work.
Horrid Wilting's only stipulation is that it be a living creature. Fire elemental, is a living creature (SRD:Unlike most other living creatures, an elemental does not have a dual nature—its soul and body form one unit. When an elemental is slain, no soul is set loose.)
Don't make it hard on yourself by adding 'sense' to the equation. It doesn't have to make sense, and when you try to make sense out of it it becomes subjective.
Its not hard to make this house rule adjustment. It doesn't have to make sense for the game to work, but it might be cooler to have themed spells and monster work according to their flavor descriptions rather than a strict appliation of RAW.
It is a water draining spell, having it not work on non-water elementals seems thematically fine.
It seems to me you have to work hard to make it fit descriptively in affecting fire elementals and ultimately say, "that's the way it works because of how the rules work." which isn't as satisfying when trying to present an in game explanation.