Another good way to remove silver deposits is to use Potassium Dichromate.
It's also corrosive, but perhaps a little better than Nitric Acid!

Karen Pawlowski wrote:

> Hi all,
>
> An associate of mine, Kumathu Paulose, asked if I would post the
> following method that he developed for anyone who wants it. I haven't
> tried it, but I know that he is a very experienced histotechnician.
> I hope that someone finds it useful and I'm sure he would appreciate
> feedback. Just post it to the net and I'll make sure he gets it.
>
> Karen Pawlowski
>
> Removal of Silver Deposits from Glassware and Plastic Dishes
>
> In the histology laboratory, metallic silver is often deposited on
> glassware and plastic dishes after the use of silver stains.  This
> deposit of silver can be easily removed within a few seconds by the
> following method.
>
> Pour concentrated nitric acid into the container having the silver
> deposit. The metallic silver reacts with the nitric acid to form silver
> nitrate and hydrogen is liberated according to the following equation:
>
> Ag2 + 2HNO3 -> 2AgNO3 +H2(released)
>
> All of the silver deposits from the container will be removed in less
> than one minute.  This reaction needs to be carried out under a fume
> hood wearing gloves.  Care should be taken when handling strong acid.