I heard that grinding citrus rinds with a food processor and then sprinkling that with the pine shavings helps to neutrolize the odor. I read on this site that they shouldn't be fed citrus, but is this way acceptable?
Look at the food grade DE link that's in my signature ^, I'm putting together a section right now that has links where you can buy it. We get ours locally through Custom Milling as the co-op, feed stores and TSC have never heard of food grade DE before.
Some feed stores carry Sweet PDZ or Stall Dry that also help eliminate odors.