For what it’s worth, I never ever pickle after enameling. It always
etches the enamels (even the blues - all colors, all leaded), and
even the mildest etch ruins the beautiful enamel sheen. Since I also
use silver, the cleanup is not difficult. First, I cover the
enameled area with blue painter’s tape. It adheres well but never
damages the surface. Then use a mild abrasive like a 3m radial disc
brush in a fine grit or possibly a pumice wheel. If you feel pickle
is absolutely necessary, use the painters tape then apply pickle with
a paintbrush only to the silver areas & rinse within 15-30 seconds;
reapplying as necessary. Tarnex can also work in this way.
It’s extremely difficult to fix the etch - it clouds over if
re-fired and is very difficult to polish out. I’d avoid it at all
cost.
Good luck!