Alcohol is plentiful in D4, and is David's primary source if liquid it seems.
Drinking liquids restores David's Vision (used by holding
), which is ironic since alcohol does the opposite, so working on 100 Vision uses and this is recommended.
Some agave tequila is on the kitchen table and never runs out, but David can only drink afew shots each visit (you'll need to Dive each time to replenish uses).
There's some beer in the refrigerator as well, grab that too.
Otherwise, you can use a vision, or all of them, then visit Cat Amanda in a Dive to replenish them by buying tequila, vodka, whiskey, etc (usually the last on the list as they restore more and cost more).
Buy a new liquid each time, as they count towards the food list achievements too.