Whilst fasting and taking Urine the Urine gets more and more chemically in smell and aftertaste which I put down to Ketone concentration. Its very unpleasant and I certainly do not like it, you will notice this more on day 3 and definately day 4. You'll understand when you encounter it.
Real Salt is needed at a ratio of 1/4 teaspoon (1.25grams) for every 1 litre of water drank. Whilst fasting I've used salt and Kombucha but you can just use your Urine and water then when the fast is complete just take a bit more salt that the ratio to water such as 1/2 teaspoon for a week instead of 1/4.