The new RNG reporter makes using Sweet Scent a lot easier, so you need to go ahead and do that. You use Elm Calls to verify your seed, yes, that is correct. You can paste your seed hex into the main screen of RNG reporter and choose Method K (HGSS) and then hit generate. This will show you the elm responses all the way up to your target frame. Keep on calling elm until you are one below your target frame and then use sweet scent. You should get the Pokemon that you desire.
For example, if your pokemon is on frame 20, you would need to call Elm until you are on frame 19. Then you use Sweet Scent and your Pokemon appears.