Removing Silver Nitrate

 provide a spray bottle of weak thiosulfate to the class whenever silver nitrate is required as this will prevent any silver spills from forming stains. The use of newspaper to cover the benches is also encouraged. 

Silvo metal polish

or

1) for old stains use conc acetic acid before using

2) potassium iodide followed by water.I have also found a 55 solution of sodium thiosulphate works well