Collect the fish scales from one type of fish. For example, freshwater tilapia or saltwater snapper fish are good sources. Do not mix scales from different fish species.
Rinse under running water.
Soak the scales in 5% white vinegar for 2-3 days, which will help acid cook any tissue that remains attached to the scales.
After soaking in vinegar, wash the scales thoroughly, ensuring that all organic material has been completely removed.