Royal Canadian Mint Coin Sets

No

Toned/ tarnished silver coins often do not decrease value and are sometimes desirable. They should never be cleaned.

I'm sure you have a nice new shiny nickle kicking around. Take your cloth to it and then look at it with magnification and see what happens.
I'm only encouraging you to do this inexpensive test so you will never ever clean a coin again.

as mentioned - please do not in any way clean your coins.

with rare exceptions, it absolutely DEVALUES the coins.




IT might be a bit of a tangent, but I want to comment on that quote;

I have observed that the 1976 Olympic coins have a stronger following, and do actually demand a premium;
I have never bought any because of the premium associated with them.

Conversely, I have found that 1988 Olympic coins can be had at a much better deal, and over the last ten years I have bought two full sets (the ones with the brass(?) token) and the odd single at face value (each coin is a full troy ounce, and has a face value of $20);
Although this may be in part to the fact that I live in Calgary where those Olympics were held...
I personally think the 1988 Olympic coins look nicer - but I am probably biased.