Well, the best thing to do is obvioulsy to dillute the soap as much as possible. As far as the sand bed, you can pretty much guarantee that that is gone, so look to replace that.
The LR I would place into a trash can and just continually let the soap leak out of it and keep changing the water every few days (all of it) for a month or two and then to test the water etc but you wont truly know until you try it in a tank so get a 10gallon, and some bait shrimp from a local fish market and drop one or two in the tank with as much rock as you can fit in there. That will tell you if it will be safe or not. If you dont want to do that then you need to hjust put the rock out in your yard for decoration.
Eddie