Urine is not distilled water. It actually contains tons of stuff that bacteria, yeasts and slime can live on, including lymph fluid which contains B and T-cells from your bone marrow. They say that its sanitary because it has a low pH and no living organisms. Sanitary and sterile is not the same as distilled, but people tend to conflate the concepts.

Urine contains many compounds other than water but because it comes from within your bloodstream where you have an active immune system it will lack yeasts and bacteria. If you put urine in a centrifuge, you will find it contains around 5% solids.

So, if you had a choice between distilled water and urine, I would urge you drink the water.