The process did NOT work on the desi plastic, however. I had to replace those with some new ones I had on hand. The process is mainly limited to ABS plastic, which covers a wide variety of things; game consoles, old computers, vintage electronics, etc. This includes old telephones from Ma-bell. I have my white card dialer apart and under the UV lamp right now bleaching. The process is safe for colored plastics, like the blue and pink sets from WECO that turn nasty colors when they fade. I will test this on mine before I advocate doing it to your priceless pink 500PU set.