What is the best way to affect my Pokémon with a special condition?

If you're looking to do it a lot, then potentially Brute Bonnet + Ancient Booster Energy Capsule, but if you just want it once or twice a game, then something like Spicy Seasoned Curry could work. I'd go for Brute Bonnet + Ancient Booster Energy Capsule if you have room for it though.