I've used Blue Vet Aptasia Control to remove aptasia. It has worked well for me. They didn't have any Joe's Juice at the LFS, but this seems to work just fine. I only have one or two pop up occasionally in my frag tank. I had peppermint shrimp in my main tank at the beginning, and I've just never seen any in there.
GSP does indeed go wild. I have the braierium (gorgonian) type, and it grows just as fast.