IMO dry fasting is easier than Water Fasts because you shut off your desire from all food and drink, focusing on rest. I dry fast every second day and have for 99% of the past 6 years - except when I travel or fall ill.
I feel more ill on water fasts. The longest I have dry fasted is around 7 days. I was pretty weak and in bed. but I was actually unwell at the time. 4-5 days dry fasting is ok... but expect gnarly breath...
yes bicarb helps you urine not coming out like battery acid.
I am currently on the first day of a 12 day limited pineapple fast and want to go into a 21 day water fast. I feel slightly over ambitious seeing as I have only ever done several 8 day water fasts, frequent intermittent fasts and short dry fast.