I have a box of this in my bathroom, and if you don't.. you should. I have tons of things I use this for, I put it in my bath, I polish my teeth with it (once a week though, I have crazy sensitive teeth) and I use it for a microdermabrasion like scrub on my face.
The key difference between using a soft "scouring" powder, and granules is that you're not cutting the crap out of your skin in order to get the dead cells off. I used peach face scrub for a very long time so I'm just as guilty. I now save that stuff for my body and I use this for my face.
It's deceptively strong, so I wouldn't suggest overdoing it and if you've never used it before, do it on a night where you aren't going anywhere the next day. Here's how I do it.
Put all of your hair up and away from your face. You want nothing hanging down at all to keep you away from hitting every part of your face, and I hate getting my hair wet. Cleanse your face like normal (unless you use something like proactiv, then I'd suggest skipping that and just wetting your face)
I used to do it instead of washing, but I found that it never felt as fresh as if I washed first. I use Timewise on my face before scrubbing instead of my usual cold cream "wash". Pour some baking soda in a bowl so that you don't waste the whole box with your wet hands. Make sure your face is good and wet, and dip your fingers in the baking soda. Rub your hands in a circular motion all around, making sure to do extra deep on your T-zone. Do your neck, too.. heck when you're done, hit the backs of your hands as well!! Scrub scrub scrub for at least 5 minutes, but I usually do 10. I actually do 5 with my fingers and 5 with a damp washcloth. Rinse well, and if you want to you can do a honey mask after. Honey masks are super ridiculously simple, just warm up some honey in a bowl, pat on your face and leave on for 10 minutes then rinse. Finish with your usual moisturizer (if it has retinol, skip it)
This makes me think that I need to do a session on home facials and masks!