MB3 166a: Scabs and Wounds on Shabbos (328:19-24)

If a non-Jew cooks for a choleh on Shabbos using the Jew's utensils is kashering required?

Using an eyewash on Shabbos.

Removing a scab on shabbos and applying oil.

Are things that are sometimes done for medicinal purposes subject to the prohibition of refuah on Shabbos?