I have taken to baking fish in a large rectangular casserole dish that I have. What happens is, the smell kind of sticks around in the dish later even after I’ve scrubbed the thing several times. Maybe I’m dreaming the impossible dream to think there’s some magical way to get it off and I’ll have to get another one for non-fishy baking.
You might try running a wedge of lemon around the fishy odor. That helps with some things. You could even let the juice sit for a while. Or maybe you could try “baking in” another odor. (I don’t know if you can bake in the lemon juice.)
I sometimes get this with my cast iron pan; my solution is to cook something mildly savoury (but non-fishy) in it, like a vegetable risotto. Typically this intermediate dish won’t noticeably acquire any of the fishy aroma, whereas something like sweet pancakes would.