Batteries ruptured, now what?

I loaded the camper on the truck today and while attaching my tie downs, I noticed a white film on the underside of the wings. A chill came over me as I recalled a post I read on the forums last week about dead batteries rupturing, while the image of my fantastic vent left in the 'on' position all winter flashed in my head. Sure enough, my batteries had ruptured.

I pulled them out and made a thick mixture of baking soda and water. I basted the battery box and the underside of the wings with the mixture and thoroughly rinsed the area. Is there anything else I need to do?

On a related note, how do I dispose of these batteries? I have heavy, leaky, corrosive items that I really don't want spilled all over my vehicle. Will a Rubbermaid container work?