YEah this works well, and is kind of common for Slaking. However, Worry seed does not work against Truant, so Gastro Acid is the better choice. If you're going to run gastro acid, be careful because you can probably predict it when you see a poison pokemon, and there aren't many non poison types that learn it. You could skill swap it, but then you have it on your teammate, and you would try to switch it to your opponent, but they would just switch out to cancel it, and by then your pokemon will have taken some damage. So Gastro Acid would be the best choice when put on a subtle pokemon.
Ps.-where did you ever get this awesome strategy? Definitely not the strategy I told you from an earlier question...
