I dry fast after 5pm every day. I Water Fast once a week.
The most I've ever done was 5 days water fast, and it was fantastic.
Just from my experience, I never dry fast if I am thirsty. The thirst feeling means you have been a teeny bit dehydrated already, and that's when dead water is released, which you want :)
But it sounds like you've done this before. Are you blogging it? With pictures? I'd love to follow.
I'm doing a Water Fast today and will be posting my eye change tomorrow. A long water/dry fast will show MASSIVE changes in your eyes!