I am pretty sure he means recording it at a slower tempo, then editing it to the intended tempo, not slowing it down using time stretching algorithms.
MattG: What DAW are you using? If Cubase, check my signature for Cubase Slip Editing Tutorial. The video is using drums as the example but the same technique applies to anything you are trying to edit (guitars, bass, vocals, etc.). In the thread where I first posted the video Joey confirmed the method in the video is exactly what he uses.