I clean the toe punch simply because there's no sense in mixing blood from duckling to duckling, if they do bleed at all. I've never had a duckling be sick with anything contagious, but this is my usual habit with some of my horse tools/instruments and I've never changed it because rubbing alcohol is cheap and it's easy enough to do. Also, I have noticed that punches can become dull quick (they're pretty inexpensive, but who wants to order more stuff they already have?) if not cleaned and not punch the holes as effectively, possibly leaving a "hanging chad" of webbing/skin, so I find it best to clean it with alcohol which evaporates quickly. Small tools I've found are always easier to clean before any goop you get on them dries.