Skip the Novus 3 additive, get some Kit Scratch Out at the local auto parts store, cheaper and a virtually unlimited supply available in most communities.

I would recommend crushed walnut shells. Get them at Petco in the reptile section, pay no shipping. It's more aggressive than corn cob. Corn cob is more useful as a final polish, if you decide to go with a 2 step process. Walnut is good enough for most everything.

briguy5:
you may want to check your local harbor freight as well. I recently picked up this for just under $45 (with one of their 20% off coupons)

http://www.harborfreight.com/5-lb-metal-vibrator-tumbler-67617.html

btw, their walnut media from harbor freight is 25lbs for $25 (and only $20 if you use a 20% off coupon which can be found in the coupon sections of the sunday paper circulars)

Yup....thats exactly what I did. But fortunately I have a Harbor Freight store about 7 miles away. Definately the cheapest solution and it does a great job of eliminating those metal burrs that the leg bolts get on them. Just make sure you tighten down the wing nut on top pretty good and check it every 12 hours of running.