Has anyone tried salivary gland Botox? I want to refine my jawline!

I only knew about square jaw Botox, but I heard there is also salivary gland Botox. I'm worried that the area below my ears looks a bit protruding, so would this be effective? I'm concerned it might hurt, so how long does the procedure take? Does Maypure offer salivary gland Botox? I was looking through their promotions but couldn't find it.