If a hand-brushed finish is what is wanted, I recommend using
jeweler’s brass brushes, moistened with water and a drop of liquid
dishwashing detergent when brushing silver or gold (PMC or any other
form of precious metal).
Brass bristles are a bit softer than the bristles on a steel brush,
but generally produce a finish that I like. As brass-bristled
brushes are used, the bristles get work-hardened and become a
little stiffer. A collection of well-used brass brushes gives one a
’library’ of finish options. Steel-bristled brushes, though
immediately more aggressive, can also be used. I would suggest using
a bit more liquid dishwashing detergent on a steel brush.
The reason for the liquid dishwashing detergent: it lubricates the
brush bristles and prevents a transfer of colour from the bristles
to the precious metal. I use the least perfumed, mildest, least
polluting liquid dishwashing detergent I can find.
I would also suggest NOT using the steel or brass brushes found in
hardware stores. These brushes are extremely stiff and too
aggressive, in most instances, for use with precious metal.
Hope this helps,