In your situation, I would do a water change to remove a lot of the Coppersafe. 50% would be good if you can. Let your fresh saltwater set up for an hour or two with a powerhead or airstone to mix it, make sure to match salinity and temperature, and then do the water change.
Once the water change is done, I would treat with PraziPro. Find some Cuprasorb to remove the rest of the copper (that isn't bound to the rock).
You can have this done by dinnertime today if you don't have other commitments. Otherwise, do it this evening. I wouldn't wait as the flukes can kill (suffocate) your fish pretty quickly.
If you are using a hang-on filter on your qt, put a new sponge and new filter media in your dt sump (or dt). These will seed with bacteria in a couple of days. Move them to your qt's hang-on filter after 3 days.
After 4 days from the PraziPro treatment, do a 50% water change to remove dead flukes. If there are any more visible flukes, do another PraziPro treatment.
If there are no visible signs of flukes, remove the rest of the rock over another couple of days. Test your water daily for ammonia and do a 50% water change if there is any sign of ammonia.
This will put you at the middle to the end of next week. At this point, your biofilter should be established in the qt (sponge and filter material) and you will have no rock (or sand). Start your treatment with Cupramine and run it for 4 weeks. Ramp the dose up more slowly than the directions on the bottle say (as noted above). I don't go all the way to .5 and generally only dose to .4 unless I see parasites (velvet or ich).
Some fish stop eating in any copper solution, so feed sparingly until you are sure the fish is eating normally.
After 2-3 weeks in Cupramine, you can do another PraziPro treatment. Again, watch for some suppression in the fish's appetite.
These types of posts will get more comments in the fish disease forum as there are more people cruising that forum looking to help on treatment matters.
Good luck.
