I accsedently got rid of extrascensorry for HO-OH and for The Poisen E4 member.
If you listen to Prof. Oak's radio Station, they'll announce a Pokemon mass outbreak every day. I steal mine from Mass Luvdisc outbreaks, and the outbreak is on Route (I think) like 19. If not 19, I mean the one right next to New Bark Town while surfing.
You can get them from wild luvdisc (50% chance), rock smash, pickup, and pokeathalon dome on wed and sun. You can also get them from Beautiful Beach, Warm Beach, Stormy Beach, and Quiet Cave in the pokewalker.
Johto: Route 32 (With Dowsing MCHN), Violet City, Cianwood City, Dark Cave
Kanto: Route 19, Vermillion City (With Dowsing MCHN), Vermillion City, Rock Tunnel, Victory Road