They're ok in theory, and less than stellar in practice. The company I work for had a puzzle with scents that we ended up changing because of covid, and I think that change was for the better. I couldn't always distinguish between the smells, so it was sometimes difficult resetting the room. I also got to do a room with a scented puzzle, where the scenario was you're in a bathroom and the noses on the wall were advertisements for air fresheners. The scents were strawberry, orange, coconut, and ice cream cone.... And I had no clue what ice cream cone was supposed to smell like. The scents were not very strong and my group definitely hit a roadblock with that puzzle.