Wow, I'm surprised about this actually. I thought it would be pretty much impossible to find SMS now that the stores are discontinuing it, but I found two branches that each had a bag lying around from previous orders that were not picked up. I had them shipped to my branch. They might charge for shipping if they're part of another company, but its only $5-7, which still beats the price on high-tech gravel.
So if you're still looking for this stuff, check a few zip codes around you, and you might find an odd branch with a bag or two.
