Is it possible to make taste of raw oily salmon less pronounced?
My suggestion would be if you don't like the taste don't buy the fish in the first place, however if you have bought fish and then found out it's too strong a flavor there are a few things you can do:


A squeeze of lemon: acidity is a well known and frequently used way to cut fatty, oily flavors
Sugar rub: coating the flesh with some sugar and letting it sit in the fridge for 30 minutes to an hour draws out moisture and the sugar will impart some flavor, just get rid of the excess before you eat it
Salt rub: similar to sugar you can do the same thing with salt, I do a mix


You could do a full cure as well but it seems overkill and isn't likely to do more than a shorter rub. I'd suggest starting with lemon and seeing if that helps, if it doesn't I'd be tempted to cook it instead of spending a lot of time and effort making it more palatable raw.