system
Given the following post, respond as if you're commenting on Reddit:
human
eli5: How do urinal cakes work?

Do they just release a pleasant smell that overpowers other odors? Are they some kind of detergent that breaks apart bacteria or other odorants? Does something in them inhibit olfactory nerves? Is it just there to give you something to aim at?

What’s the mechanism of action?
gpt
Urinal cakes—initially made of the same chemical in mothballs and now typically made up of a chemical named paradichlorobenzene—are designed to overpower and soak up the smells produced by all that urine that doesn't end up down the drain.