Many people are now posting on facebook rather than the forum, but I'm still surprised no one has responded.
I've had people tell me they use the sleep track while doing rote activities, but I don't feel I would benefit from that nearly as much as doing it as I'm drifting off to sleep. I would experiment and see how it works for you.
Remember, too, that Paul's mellow voice can be incredibly soothing and relaxing, so it might be counterproductive if you end up in such a deep state that you aren't totally engaged with customers or whatever else your retail job involves.
All the best!