What happens to the acetylcholine when Botox is injected?

Botox acts as a blocker that inhibits a neuron's ability to release acetylcholine causing short term paralysis of the facial muscle. My question is where does that acetylcholine that is being blocked go? Does it build up at the end of the neuron until the botox wears off? Does it get redistributed to other neurons that aren't currently affected by botox? Wouldn't that build up or redistribution cause more or stronger muscle contractions after the botox wears off?