Raise temp to 30 and add aq salt, gravel vac about a quarter of the gravel and 20% water. Do this for 10 days (I’m aware this is just slightly different to what Jeff said but this is how I cured it)
If you decide you need meds, go get some blue planet white spot cure (not sure on the exact name) or multicure.
Going to 32 degrees should be fine, my tanks have been close to that with the hot weather lately. Make sure you give them more bubbles cause the heat takes the oxygen away I think. And if you do use a medication, check the directions, cause loaches are scaleless and are usually only half dosed.