How does belch work?

Question

Can I use it multiple times after eating a single berry?

Answer 1

Belch can be used once, under normal circumstances.

The user lets out a damaging belch on the target. The user must eat a Berry to use this move. ~ Serebii

As the attack's description clearly states, a Berry is needed for one use of Belch. The only way to use Belch successively is with either Recycle or the Harvest Ability. However, only Trevenant, Exeggutor and Tropius get harvest, and none of them can learn Belch. According to the DB's moveset searcher, the only Pokémon that can learn both Belch and Recycle are Trubbish and Garbador.

Comments

Actually execute and exeggutor get harvest also.

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According to Lupus-Chan, it can be used more than one time per Berry. If you find that he's right I'll edit/hide my answer.

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According to Bulbapedia*

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According to Bulbapedia, according to Lupus-Chan :)

Answer 2

Yes.
Aslong as the Pokemon using it has eaten the berry it can use belch as many times as you want. Even after switching.

Source: http://bulbapedia.bulbagarden.net/wiki/Belch_(move)

Comments

Yay! Another gimmick like my sableye to annoy the entire database. Just kidding, but I'm gonna use this stratigy with every good pokemon I can.