There are plenty of uses for body “survival items”. Here’s a few off the top-of-my-head (LOL):

Urine
-Is sterile, and has been traditionally used (fresh) to wash wounds.
-Breaks down to form ammonia, which is also a useful cleaner and sterilizing agent
-Can be “readily” distilled (solar still) to produce potable water
-Can be used as a fertilizer, when diluted with water (about 1:10), it actually contains a good NPK ratio for plant growth
-Tanners soaked animal skins in urine to remove hair fibers
-Urine is said to be excellent at removing greasy stains from fabric

Hair
-Has been used for production of cordage or millennia
-It is Not a good tinder or kindling, it doesn’t take a flame readily
-Those with a long fringe, or long hair can pull it over their eyes to provide some protection from glare (in the sun or snow)
-Hair provides warmth and (anecdotally) protection from some insects like mosquitoes
Hair is a survival item which you really need to work on well in advance of any situation, some of us are better endowed than others, but I’m sure that appropriate hormone therapy could sort out any deficiencies !

Saliva
-Licking wounds - human saliva has been shown to increase the speed of coagulation for human blood, this process also removes dirt from the wound area.
-Soothes cuts, stings and minor burns
-Lubricant
-Spot cleaning

Teeth
-Breaking and grinding (eg chewing a stick end to make a brush, or softening skins/cordage)
-Holding items as an “extra” hand