Multiple realities(covers information from several alternate timelines)
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. (DS9: "Armageddon Game")
In an alternate 2371, Tom Paris used sterile pads to clean Kathryn Janeway's head wound while inside Pe'Nar Makull's hiding place. (VOY: "Time and Again")
The shooting schedule, p. 8, lists cotton and alcohol as props to be used instead of these pads.