When I got treatments from Acupuncture for my chronic heartburn, some of the student Acupuncturists applied a single mustard seed to my ear with a sticker. It was the weirdest thing, but there is some effect that mustard seed has to the skin that should be respected. Some people say if the mustard is left on your skin for too long, it can cause third degree burns. So, maybe it’s not such a good idea to sleep with a poultice on. But how long is reasonable?
The information about mustard seed poultice or skin application is spotty on the Internet. Who really has fully studied the effects of the seed? Does everyone really have to do our own experiments and find out for ourselves? It would be nice if there was a forum that could bring everyone’s experiences together and collate what seems to be the most popular uses for mustard seed.
This seed is available on many grasslands. I have picked some myself many years ago. Although, I failed to test it out on my skin. I was more excited to figure out how to eat it instead. But I think my experiments with it are part of the reason I suffered from heartburn for a few years afterwards. I experimented with this very hot seed in dangerous ways.