Kelpie Urine is a known remedy for seasickness and is stored in a vial.
It was mentioned that it is the best way to regain equilibrium or balance, and is used as a last resort if other cures fail.
It can be noted that Keefe threw a vial of this overboard while on a boat traveling to Ravagog with Sophie, Blur, and Lady Cadence in Nightfall due to its extremely unpleasant smell.
Official Description
Most only use this remedy as a last resort, but it's the absolute best way to regain equilibrium, when fighting vertigo or seasickness
Quotes
“'Kelpie urine is the absolute best way to regain your equilibrium.'
Keefe tossed the vial in the river. 'Not even if I really was dying.'”