In 1990, at a prominent U.S. dental products manufacturing company known as CDI, a unique new liquid was developed with the specific purpose of removing impurities from plastic and metal surfaces. Upon release of this product, the Director of CDI found that not only did this liquid remove surface dirt, impurities, gums, grease, varnish, inks, etc., but it also quickly removed surface PVC (“green-residue”) from coins as well! Better yet, the liquid did not disturb the metal in any way! Surface “toning” was left completely intact while contaminants were rinsed off with ease.

After repeated tests on different metals and on many surface problem coins, the liquid removed residues consistently while leaving the original coin surfaces undisturbed! Since the discovery of this cleansing effect, the Director proceeded to use this liquid treatment before sending off coins for "slabbing" to the certification services and this liquid has remained undetectable for the last 24 years!