If the slime is gone, now is the time to watch for secondary infections. Since your fish is/are either still sick or on the mend, I would try to separate the 2 clowns until they are in better shape. The last thing either needs at this point is determining dominance. Their main goal should just be getting healthy again.
Copper will treat ICK as well as Crypt ( a.k
.a. Velvet) so if the fish are still showing white spots, you can treat them with the copper. FW
baths will also help get rid of the white spots as well.
Be aware of some things: Just because the spots are not on the fish does not mean the tank is cured of the infestation. Most parasites have different stages and some of those stages are off the fish. This is why is is always a good idea to treat parasitic infestations in a separate tank. The goal is to get the fish out of that water once the parasites have left the body. The next thing is secondary infections. The newly "cured" fish should be maintained in a QT setup for at least a couple of weeks to ensure that they don't relapse or come down with any secondary infections. Consider each area that a parasite was attached to as an open wound. It would need good clean sanitary conditions to heal up those wounds so don't be in a hurry to put the fish back into your main display tank. Make SURE the fish are normal, healthy and active once again before they go back into your display tank. Don't rush.
Hope this helps