2 uses not mentioned.
In the manufacture of cloth (tweed) in the Outer Hebrides, the cloth was soaked in urine and then stretched by hand by a group of women (don't they always get the best jobs!).
The process was known as 'waulking' and was done to the accompaniment of singing, (hence 'waulking songs').
Some Travellers, when they wished to marry, would pee into a bucket and when it was swirled round they were considered joined for life.
Jim Carroll