Sonic showers are of course a well known and accepted technology in Star Trek, perfectly capable of replacing traditional water-based showers or baths (which may still be used recreationally.)
What happens when one only needs to wash one's hands, such as after using the waste extractor or before prepping some non-replicated food?
Are there sonic faucets of some sort, or are traditional soap and water still required?
Canon and/or EU answers are acceptable.
