a way to avoid this is to use your other hand to manipulate prisoner stones) contamination happens ( oil gets transferred indirectly from black to white stones a bit extreme, admitted.Dumping A Pile Of Stones Out Of The Bowl (or keep them in your hands).Dangling a Stone Above the Board While Thinking,.don't use natural oils or waxes such as bee's wax - it is ok for some time, but will destroy the surfaces of shell stones after 3 or 4 decades.keep stones in their respective bowls, preferrably in a protective cloth (see rgg).think of oil from board or hands - that's why both should be clean.One can get carried away in an attempt to preserve stones best is to keep an eye on them and just wash from time to time. See also this AGA article How to Clean Go Stones I think caring well for the stones is probably the best thing to do. Following the descriptions of the strips, it preserves the teeth, so it might be better for the stones too. Also what I found are dental strips to whiten teeth. Following what I learned, shorter periods within the H2O2 and repeated more often could be better for the cell, but I'm not sure.

Also the H2O2 is stabilized usually with 10% phosphoric acid to make it safe for private use. My research on the cleaning process showed that H2O2 reacts in a way that an acid is created. User - Aselan: I found a nice website with a good description on how to clean stones that turned yellow after intensive use (with the result that they're white again) and how to apply the wax and which to use: In germany you can get it in some supermarkets or in the pharmacy, chemist's or drugstore. It's pure sodium Hydrogen carbonate, also known as sodium bicarbonate, bicarbonate of soda or baking soda. User - Aselan: I use Kaiser Natron (following link leads to a german page, I'll give a description after the link so that you can look for local products) it binds and neutralizes acid and is very mildly alkaline. try to avoid soaps with perfumes and dyes.

Kaiser natron wikipedia