At Walmart, K-Mart, Home Depot, or your local sporting goods store, look in the hunting and fishing departments for EZ-Lap diamond sharpening stones. Thehy are 1"x4" size and are a decent flat diamond stone for around 6 to 8 bucks. In the same departments look for a pocket fish hook sharpening stick........3/16" diameter rod, flat on one side, diamond coated, that will work for using the round side as a slip stone on the inside of the gouge.
You will also find Smith diamond stones there for around $20-40. These are 3"x10" or so and work well for a bench stone. I think they come in 2 or 3 grits.....I have only the fine grit, and it works well for chisles, gouges, knives, and even axes and adz sharpening. Some of these have oval shaped holes in the surface to get rid of the slurry or debris, as you sharpen, and some are solid surfaced. the solid ones run a bit more because of more diamond particles on the surface, but work better for small sized carving tools.
None of these diamond tools require lubricant, so that simplifies the sharpening process. They do have to be washed off with soap and water occasionally, but that's a quick clean-up job.
This may open the discussion on the best type of stones, but you asked about what was available at the discout joints........I'd suggest you patronize your local sporting goods store if possible.....they help out on a lot of other questions you may have and will special order all kinds of stuff for you.
Check here
http://www.littleshavers.com/Books11.html for a few books on sharpening. It's better to have a good reference than to rely on verbal or text to explain the sharpening process.
Al