Are the Oscars having any trouble with breathing due to the high temp? If so, try to provide them with some extra oxygen by adding an airstone or increased current if you haven't done that already, they should be fine then. If possible the temp should be kept in the high range for about 5 more days to be safe.
The thing about ich is that you have to catch the parasite in the free swimming stage, the disappearing of spots doesn't mean there are no parasites present in the tank anymore, and you don't want to have it again.
But it's a good sign already that the spots are gone, sure looks like you worked that out well

Maybe after finished treatment you could add carbon to your filter for a day or so to remove the med.