From Bones Bearings Website:
https://bonesbearings.com/support/cleaner/Solvents we recommend are
Acetone, Methyl Ethyl Ketone, Citrus cleaner, and Denatured alcohol. All of these can be found in the paint section of your local hardware store.
Products we
DO NOT recommend are petroleum-based products like; paint thinner, gasoline, kerosene, lacquer thinner, turpentine or anything that contains tolulene. These solvents aren’t adequate cleaners and should not be used in the bearing cleaning unit.
Whatever you use, make sure to dry your bearings and add the lubrication to them as soon as possible to keep them from rusting.
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You dont need to buy that bearing cleaning unit, just shaking it around in any small container will have the same effect. could use an old pill bottle, tupperware, etc.