Otec Eco-mini Polisher/ cleaning sand blasted silver

I think it was Martin who mentioned the Eco-mini polisher by Otec a
while back. I was thinking of purchasing one but before I do, can
anyone tell me if they work on all metals and finishes. As well as
polishing repairs I was also considering the cleaning of shop stock.
By far the hardest items I have to clean are small silver pendants
that have a sandblasted finish which up to now I have only been able
to deoxidise with Tickopur, which is o.k. but I’m sure there is a
better way.

Thanks in advance,
Neil KilBane,