How effective is underarm Botox?

As the weather gets warmer, I'm getting so stressed about underarm sweating that I'm considering getting Botox...

Is the sweat reduction effect really guaranteed?

I am curious how long it lasts after one injection, and I also want to know if it returns to normal.

I'm also worried about potential side effects or the extent of pain.

If anyone has tried this, please honestly let me know about the effectiveness or your satisfaction.