Drinking lots of water won't help you lose weight. Dry fasting can induce more weight loss, but with that can also come greater detox symptoms so you have to weigh the consequences of 'doing it tougher'. You also have to be prepared to drink water if you need it and not be so set on a time limit with your dry fasting. Obviously thirst comes on quicker than hunger and the consequences of not recognising your thirst are more immediate than hunger also. Dry fasting is awesome, the ultimate in fastin in my opinion, but not to be taken on lightly.