I still have a coupla boxes of medi-swabs left over from the part-time job when I retired a year or so ago. (you know - the individually wrapped 2cm square swabs impregnated with iso-propyl alcohol that your doc -or usually nurse nowadays- cleanses the skin with prior to taking blood)
They work well, don't fill the cockpit with fumes and when sealed seem to stay moist for ever...........
Safe flying
Cusco
Should have added that they get chinagraph marks off a treat too...............