I knew I left chat too early.
Grab a wet/dry vac first, then after you've gotten out what you can that way, scatter some silica gel beads in there. That'll suck out any remaining moisture. You can gather them up, cook them, and reuse them, or just toss them.
Better, make a mesh baggie full of them. Don't have to pick them up that way.
You can get silica gel at crafts stores, it's used to desiccate flowers for arrangements.