Polishing compound staining argentium?

I’ve been reading the polishing thread with great interest, having
had zero success with polishing except in a tumbler (which can’t be
used in every situation). The biggest trouble has been with wide (1.
5 inches) silver cuffs. I originally tried various buffing silicone
wheels on my hand held rotary tool (I found that the abrasives in
these wheels were sufficient to remove light scratches), but on a
large surface like a cuff, I’d see the paths left by the silicone
wheels. I tried a flap wheel type of attachment, but it didn’t
polish up the surface per se, but did hide its own marks by creating
new ones. Then I tried a variety of buffs and compounds, including
Zam, rouge and Fabulustre. I like the Zam despite the thick black
coating that it leaves until I go at a higher speed and then it
disappears… or so I thought. I discovered an tea coloured
staining on my pieces, when I brought them into daylight! Am I
tarnishing the pieces somehow? Reminds me of the first shade when
putting a patina on - a light bronze. Very light. Polishing cloths
didn’t remove it. Only pickle seems to remove it. Just wondering if
anyone has any advice for me? I’d like to get that nice shine,
without staining the pieces! Thanks