Yeti Pee is a yeti discretion. that takes the form of a strong-smelling golden sludge. It is an effective burn medication that is used to take the sting off the worst burns.
After being applied, it needs a minute to sit before taking effect.
Elwin usually recommends the patient who used it to wash their hands about twenty times to get rid off the smell, as it can stain a person for days (if not washed off).
Sophie took an extensive shower to get rid of this putrid smelling ointment's effects.
In Everblaze, Elwin mentions that this liquid is hard to come by, though he uses the comparison later that it would be easier to fill a lake with it than get his hands on ogre substances. Sophie uses it in Keeper of the Lost Cities and also narrowly avoids using it in another situation later on.
This strong-smelling golden sludge can be hard to find - and even harder to wash off. And it's not particularly pleasant to use. But it's the best way to treat serious burns.