It is such a small amount of zinc in two or three conduit nuts that you would never notice any issues. If you properly seasoned it you probably would take car of it or just burn the nuts on a propane grill on high for 10 to 15 minutes that should do it also. (or with a weed burner) As for the caps on the end of the pipe nipples those will be on the outside and should never get the heat on them that will vaporize zinc. Just my opinion.
