system
Given the following post, respond as if you're commenting on Reddit:
human
[Harry Potter] If muggles were able to buy spells and potions as single use devices, what would be the best selling items?

For example, one Alohomora device would unlock exactly one lock.

Also, assume that muggles accept a magical culture.
gpt
Love potions would be the new roofies. Confundus charms for similar purpose. Summoning charms to steal things. Crucio curses for sadists and interrogators.

On the less pessimistic but still jaded side, kinky weird stuff. Imagine being able to polyjuice into a movie star, supermodel, etc for a bit of next-level roleplay.