Scratch-n-Sniff Scents That Never Caught On

Con funk (Google it if you don't know).

onion and garlic

old tuna casserole

sardine

litter box

road kill surprise

Ammonia and Bleach mix

Swamp Butt

Mermaid.
Because they can't catch one.

Lochness.
Too evasive.

Pikachu.
Too electric.

Dust bunnies

manure

old work boots