(Mouthwashing)
I think the overall significance of mouthwash in the story is relatively low, outside of Swansea's use of it, but that makes metatextual sense. After all, it wasn't just useless as a disinfectant -- that amount of sugar content would make Dragon's Breath useless as a mouthwash. That's what these people are sent on a year long journey to export -- worthless, functionless dollar store shelf filler better used for a moonshiner's chaser than its actual purpose.
Ooo- like it's the reason for their entire expedition but it's nothing more than cheap, low grade dental hygiene care that they're risking their whole lives around.















