No. Formalin is the cure for brook, although most victims don't survive anyhow. Copper is used for velvet.
Velvet has a velvety sheen to it and is best seen when looking head on at the fish. Brook will have peeling or sloughing skin. Brook is usually the parasite if the victim is a clownfish. Google images of "marine brooklynella" and marine velvet" (Oodinium). You have very little time with either, a pic would help diagnose what you're dealing with.