It is reported to be excellent for nausea regardless of the cause. Fresh ginger may also be used. I have not mentioned it because it is more highly perishable than when dried, and cannot easily be carried around. With so many convenient forms this versatile and effective plant root is high on my list of natural remedies. You can substitute a teaspoon of sugar for a Tablespoon of mirin, or an equal amount of sake.
Dry sherry is a potential but inferior substitute.
Scrub the ginger under running water as you would a potato for baking. Blanch in boiling water for one minute and drain. Combine mirin, sake, and sugar in a small pan. Bring to a boil, stirring until the sugar has dissolved. Place the ginger into a sterilized jar and pour the cooled vinegar over the ginger.