I did a 29 day water/urine fast last year. The tricky part was breaking the fast, I moved to a Buddhist style 18 hour a day fasting regime.
But still my appetites were kinda outa control. I did stick to raw foods mostly.

This year I'm planning to do a 60 day water/urine fast, with more focus on the aged urine body rubs. Will try to do it three times a day like the Hindu yogis. Not easy!