I have had mixed success with this. The label states "not for use on nickel-silver, stainless plate, stainless nickel, chromium plate, worn silver or artificially oxidised silver,pearls, corals, opals, mirror backs or porous materials."
Not being a metallurgist, I don't know which of my 'silver' items fall into the excluded category, and I was disappointed that I couldn't dip items with beads or stones. I dipped 5 silver chain necklaces, and several pairs of 'silver' earrings, all heavily tarnished. Some of these turned back to shining silver within a minute, excellent result. Others lightened up after 2-3 minutes, but remained somewhat tarnished, although some of the tarnish wiped away with a cloth when I took them out. Two heavy pairs of 'silver' earrings have gone a funny colour, sort of silver with hints of brass showing through, so I guess they were the wrong kind of silver. The necklaces came up well apart from one which is small square-cube interlocked links, there is still tarnish in the crevices. Later I dipped, as a last resort to make it wearable, a silver chain and bead necklace. The 'silver' came up somewhat brighter, most of the plastic beads survived unharmed, a couple lost their colour and went very flat. The odour is not very strong although I was careful to use it in well ventilated conditions. I was also concerned to read on the label that there is 'limited evidence of a carcinogenic effect', which made me nervous. Better than trying to wipe things with a silver tarnish cloth though.