Did you know stale urine is one of the best and cheapest cleaners and conditioners for really dim wool?
Keep urine for a fortnight in a closed container such as a plastic bucket with a well-fitting lid — to allow the ammonia to develop.
Apparently, it is unsurpassed for leaving the wool in a fine soft condition for dyeing, or as a conditioner after dyeing to counteract the harshening effects of mordants like ferrous sulphate. Urine was used extensively in the Bradford blanket trade until recent times and is still used on wool in the Scottish Highlands and in Africa, India and South America.
Urine can also be used as a ferment for woad, indigo, and some lichens.