Clearing out other languages and other architectures etc ... what the poster noted.
I thought they meant there is some kind of boot up option to run in only 1 language but looks like monolingual is an application.
Yes, as they said, they use
Monolingual, which I've used with success on Leopard and Snow Leopard.
Be aware that extreme caution should be exercised when using such apps, as deleting certain languages or architectures can create significant problems. At best, deleting these things may buy you 1-2GB of drive space, but will not improve your system's performance. If you're not certain about what you're doing, don't delete anything. The small drive space savings are not worth the risk of potential problems.
Does it work well in 10.7.2?
I don't know if it runs on Lion. Their site doesn't seem to indicate that it does.
It looks like you are an advocate of manually de-installing things instead of using most of the clean up type utilities if I understand some of your postings.
In most cases if you just want to uninstall an app, simply drag the .app to the Trash. You don't need an uninstaller app to do that. If you're interested in removing all traces of an app, in order to free up disk space, use the manual method, as no uninstaller app is as thorough as the manual method. In either case, no app removal software is needed.