No, I'm afraid not (at least not with any of the costumes I've seen so far). I'm working within the framework of the game. The game already has wet shirts for some of the outfits, although a lot of the time the effect was so subtle you wouldn't even notice it. For example, Christie 03 outfit has a wet map, but the actual texture almost doesn't change at all. I tried making a mod for it, but I wasn't satisfied with the results. For some reason, the right nipple just reflected light weird no matter what I tried, so I doubt I will release that one.
Now, Helena 08 has a wet map, but just for her pants. It might be possible to make it appear she has gone commando, but even so I wouldn't put any details in there, at most, I might have some bush slightly show through. Right now, I'm wholesale dumping each character's maps and looking for anything interesting. I feel like I'm reaching the end of this project. There are some more wet maps I'd like to do, but real life is demanding more of my time for right now. More packs may have to wait for a few days. Maybe next weekend.
I've looked at some of the costume pack DLC's on Steam, but there is no way I'm paying that much for them. Maybe if they get some "Xtreme" price cuts during a steam sale, I might look into them.