Not sunlight, of course. No, the solution is to abridge and simplify the sucker.
Holy water, Batman! Wouldn't that adulterate him? It sounds indecent!
No need to cast aspersions; the Count has been (mal)adapted countless times in English alone. Once more--even once per major auxlang--should do no harm. And much of the story could be left intact, including most of the main characters' dialog. This isn't Tom Sawyer, which I believe has been translated into Esperanto, and whose dialect is a major part of the story. Most of the difficult bits of Dracula could be summarized easily enough.
There would even be a useful long-term effect: when the auxlang and its user base have matured enough for the complete novel, the abridgement could be used as a basis, so only the summarized bits would need to be translated. The rest could just be tweaked a bit.
In any case, this sort of thing has already been done. One of the first long Interlingua texts I encountered online was an abridgement of Pilgrim's Progress (translated by Paolo Castellina), and there's a short version of Robinson Crusoe on the Mondlango site.
Even so, this is at least an intermediate-level project--the sort of thing suitable to Ido and Occ, for example. (As already noted, Eo and Interlingua could manage an actual translation.) Other auxlangs could technically manage it--I suspect Sambahsa could, for example--but they don't have the user base to justify it.
Next time I'll try to explain the levels of development for various auxlangs.