Pokemon EP8 - The Path to the Pokémon League Filler

On the way to Vermillion City, Ash meets AJ, a Gym Leader at an unsanctioned Gym who has 98 wins and zero losses. They battle, and Ash is surprised that AJ's Ground-type Sandshrew can easily beat his Flying-type Pokémon. (Flying-type Pokémon are usually strong against Ground-type Pokémon.)

Ash and his friends later see that AJ puts his Pokémon through very tough training—he makes his Sandshrew, normally weak to Water-type attacks, train in a swimming pool! Although Ash doesn't approve of the intensive training session, Brock is impressed. Ash begs for a rematch, but AJ refuses. The two argue a bit and when they fall into the pool, AJ's Sandshrew goes missing.

Are AJ's training methods too tough? Will Ash get his rematch? And what happened to AJ's Sandshrew?