Brandon,
I take out my rocks and fake plants every week at water change time. I put them in a bucket with about two gallons of water and half a cup of bleach. They soak while I vacuum and drain the tank. By the time I am through draining the water, my plants are clean as the day I bought them. I rinse a couple of times and then add some dechlor. Swish them around a bit and put them right back in the tank and refill. I've been doing this every week for almost a year and I haven't had a problem yet. You could use less bleach than I do, but it might take a little longer.
Just my experience,
Jman