I think he saw the rule34 of himself. If that's the case they're not enough showers in the world to clean him.

This is why it would be preferable to live in the world of Pokemon than to have Pokemon live in our world. There aren't enough Pokephiles in their world to make this shit happen. Poor Lucario. Blessed with civility and intelligence, and he used these skills to look at pictures of him and other Pokemon on the internet.