Sterile pad
Sterile pads were standard components of medkits. 

Though ostensibly for the dressing of wounds, Julian Bashir used some in 2370 to clean off corrosion on the contacts of a subprocessor. ()

In an alternate 2371, Tom Paris used sterile pads to clean Kathryn Janeway's head wound while inside Pe'Nar Makull's hiding place. ()

Medical equipment