What are the advantages of Mean Look?

Question

When you use mean look and the opponent uses Perish Song he made his or her death wish because they can't switch out but you can.

Answer 1

No opponent would use perish song after they have been locked in with mean look, and is not very likely to occur to have both use the respective moves in the same turn. Plus in those 3 turns, you pokemon will take a beating since it has to stay in to keep mean look in effect, so even if you successfully faint your opponent's pokemon, you are left with a weakened pokemon that can easily be fainted by your opponent's next pokemon.

Answer 2

Use toxic then mean look. After that use protect and a healing move. You will slowly kill them with the poison.