I just completed a lengthy quarantine of a leopard wrasse. It is detailed on page 5 of my build thread:
https://www.reef2reef.com/threads/idocs-first-reef-tank-build-75g.317135/page-5
Leopards are notorious for having internal parasites/worms. I started with 2 leopards and ended with 1. The obe that died was due to internal parasites...I didn't treat quickly enough for this during my quarantine process! If the fish seem to arrive healthy even after a few days, I would treat with General Cure+Focus for 14-21 days prior to copper...but of course doing it after successfully teaching them to eat frozen food. I attempted medicated food while treating copper, but it didn't work. My healthy leopard would show strange swimming patterns after eating the food, so I stopped med foods and the behavior stopped. Plus, the copper suppresses appetite anyhow. By the time I finished copper, the infected leopard wasn't eating at all and slowly went downhill. I've read that leopards and other wrasses have thicker mucus coats so less prone to ich/velvet...so, i would worry about the internal parasites before copper treatment.
If treating with clowns, then you should consider eventually treating the water column with General Cure instead of only PraziPro. GC also has Metrodonizole in it with th he Praziquantel which helps with Brooklynella... which cleans are very susceptible to carry as well.
Definitely use a dish of sand for the wrasses to bury into. I think this helps with their stress levels. Also don't be surprised if the leopard buries into it for several days without coming out!
Good luck! My healthy leopard is doing great in the DT now with the other fish. I took about 3 months to slowly quarantine her, though.