If you can use Fly and have a high level Pokemon, go to Mauville Town and go up smash the rocks and fight the interviewers. Make sure one of your weak pokemon has an Exp. Share and is battling. If you fight the reporters when both Pokemon are Lvl: 39, you can make more than 2000 experience points in one battle for your weak Pokemon as long as they stay in the fight for the entire time. I played in the Battle Frontier for 10 minutes with pokemon somewhat raised that way (I have a that was a Snorunt at level 28 and has pretty good attacks, a Sceptile that was raised since level 43 that way, and ,my pride and joy, my Flygon that was raised since it was a Trapinch at level 21. It knows Dragonbreath, Fly, Sand Tomb, which I'm going to replace soon, and Flamethrower. They're all level 50).The reporters are to the north of Mauville, behind the trees right after the breakable rocks, to the left of Mauville, directly across the water, and outside of Fortree, all the way to the left. After you beat them there, they will repeat that and it will go in a never ending cycle ( seriously, I beat them 112 times raising 42 Pokemon).If they don't have their Pokemon at level 39, just keep fighting them until they do. It never fails, unless you are completely horrible. YOU OWE ME!!!!!!!!!!!!!!!!!!!!!!!!!