Step 1: Make the Pickling Solution
Step 2: Heat Up the Mixture and Stir.
Be careful - vinegar is a weak acid. An aqueous solution of Ethanoic Acid formerly known as Acetic Acid. If you get it into your eyes wash them out immediately.
Other than that the solution is quite safe - after all you do put it on your fish 'n' chips!
Step 3: How to Use.
I use a clip lock container. Put the lid on and shake. Leave until the scale is removed. Usually half an hour will do the trick.