Crossy pretty much said it all. Just remember to make sure that the bar is completely white, sometimes there's a little bit left. To check, just press start, go to Pokémon, and press summary for the ready-to-be-purified Pokémon. If it tells you to 'undo the final lock!' then it's ready and go to the Agate village altar-thingy. To get there, you go into town. Just walk straight, and if it's your first time here turn left then go up to the house with the tree growing on it. It's at the peak of the village. When you get there, talk to 'Grandpa', and he'll have to run out. Then, go back to the entrance. Go straight, then turn right, over the bridge. Go down the hidden ramp that's just above the bridge, and go through the hole. Make sure you have good Pokémon with you. You'll have to battle 3 times. I would advise beating the first guy, going back to the Pokémon center, healing, then going back. Etc., then you'll see 'Grandpa' and his Pikachu battle(and lose!) to the Snag'em member. Then you battle him. When you win, the grandparent will thank you and then 'Grandma' will get you a stone that lets you purify pokémon with the relic in the grove you just battled in. Any other questions?
General, if you're not using it, could I have the army for a few days?