I think maybe if you essentially lopped off the final 1/2 to 3/4 inch of the narrow end, and round it off they might be ok for soap. Wouldn't tend nearly so much to wear away into a point. Still going to get kind of awkward to hang on to in use, I think, but I could be wrong.
Those are way cute, toxikon! I do have kind of the same concern about your horns that I have about the bigger ones, though, that they'd tend to wear into sharpish points. I wouldn't dare try to sell such a thing, though I would be ok gifting them to people I knew had some common sense. It could just me being overly cautious, that happens sometimes.