They are BOTH right with that. In order to do it ASTER, give your Torkoal an EXP, Share so it can get the bulk of the EXP points, as well as leaving it in the battle.
If you dont like it there, then try heading for the Sky Pillar (if in Emerald) or Victory Road (if in Ruby or Saphire). Both give good bits of EXP, but in Sky Pillar watch of for exploding Claydol. o.0