My grandfathers solution, was, you guessed, it, running a humidifier for years on end... he had it set up so the tub auto-drained into the drainage hole next to his water heater. YOu could probably put one on a timer so it wasn't annoyingly loud while you were down there, set it to run when you aren't around...
how about a trashcan full of sorbigel?
lol
"Maybe in order to understand mankind, we have to look at the word itself: "Mankind". Basically, it's made up of two separate words - "mank" and "ind". What do these words mean ? It's a mystery, and that's why so is mankind." ~ Jack Handey