No matter how hard I scrub my 5-gallon plastic primary fermenter, no matter how long I let it soak full of diluted bleach, I can't seem to get rid of the smell of wort once it dries.
Am I doing it wrong? Is this tainting my beer?
"Be bold, and mighty forces will come to your aid."
Standard. It'll never go away completely.
You are fine.
But do not "scrub" it with anything abrasive.
It is important that you do not scratch the inside because the scratches can hide cooties from the sanitization process, which will taint further batches.