I think it is more likely that the toning is a secondary toning from being stored in a coin album after being cleaned/dipped. The real problem is that the 1922 is a common date and readily available in mint state grades for modest prices. Toning enthusiasts look for the combination of color and luster when paying premium prices. Since this coin is circulated, the toning is irrelevant, and the coin has no numismatic value, only intrinsic value.
I think if you artificially tone a coin you would be trying to enhance it's eye appeal. This coin looks like crap to me. I don't agree with the sellers XF grade. F-12 at best to me. Worth bullion value.
Sorry, terrible looking coin. I wouldn't buy it for any reason, that means I wouldn't buy it for half price even. fugly