One word-sulfur.
Weigh out approximately 11 g Sulphur powder.
measure out 1 litre of vegetable oil using a measuring cylinder.
boil a kettle full of water.
stir the sulphur and oil in beaker or jug until the sulphur dissolves as much as it can pour 250 ml of the mixture into each of four beakers (or jugs) pour 500 ml of boiling water into a beaker.
pour 500 ml of boiling water and some washing liquid into a beaker dip object in the first beaker with sulphur and oil in it for 1 minute, swirling the object
dip the same object into a beaker with the washing up water in it and swirl for 30 sec
dip the same object into the beaker with the clean boiling water in it for 1 min (approx), swirling it all the time.
The colour should come up gradually- it will change colour even after you take it out
If you can't get a hold of any sulfur powder,boil an egg and use the yolk.Place item in a baggie and leave it in the fridge for a few days.