I also don't know anything about NA but I've worked the AA steps for the past 18 months on my own and it's worked for me. I've always been a very solitary person so I just couldn't get into the whole sponser thing and when I was going to AA often in the beginning and I would say "I will never drink again" I was told by my temporary sponsor not to say that to just "take one day at a time" and I didn't like being told what to think. So obviously I think it absolutely OK to work the steps on your own.