Grew up with a Dad who did some commercial fishing on the side, We had fresh oysters & mussels at home all the time, but though I love the flavor of them, I hate the texture, too slimy, so I cook them & puree them to add to things like gumbo.
I do love ceviche, but that's not technically raw.
PS: You can open oysters with a dull knife, but it's a slower process, because the shell resists opening if you don't cut the mantle that is stuck to it. I've seen some really ugly self-inflicted wounds caused by oyster knives in my lifetime. Never try it without a thick glove unless you really know what you're doing.