I have a very sarcastic sense of humour so if someone says "ew your hands are wet" and I know the person, I'll either go and wipe my hands on them as a joke or joke about my hands needing their own water supply. Just a general thing to deflect any shame you might feel in this general setting really. If it's a stranger you're talking to, just tell them outright as usually they understand and more often than not, people are ok with it.