You're exactly right. A chainwhip with a 2ft. piece of pipe over the end would work better. However, since a cog and lockring, both installed with either grease or loctite, only need to be torqued to about 60ft lbs, you don't really need either.

Edit: What I find interesting is that no one ever brings up the damage done to the chain by doing this. In addition to putting a lot of stress on the chain at the bb end (which is similiar to the stress made by skidding and accelerating really hard) the stress put on the chain at the cog end can't be good. You're basically crushing the links into each other. Its not the worst thing you can do, but is isn't good. As for Carltons statement about using the right tool for the right job, I couldn't agree more. Yes, you could use vise-grips to tighten your track nuts. But it will damage the nuts. I would never take my car (or bike) to a mechanic that grabbed an adjustable wrench or vice grips for every job.