"Hormone-free" NBE pills are actually phytoestrogens and such. They help your body create more of its own hormones naturally (and sometimes, depending on the pills, include hormones from animals as well).
I don't know why people say NBE doesn't work. Yes, I'm born female. But I was still able to go from a 34B to a 34DD in a little over a year. Since I decided to transition and stopped taking these pills, I've only gone back down to a 34C and don't think my breasts will ever be the 34B size they were before. I've grown too much breast tissue. I've also talked to plenty of MtFs who have had wonderful success from NBE.
The only downside to NBE is that it takes a lot of research and dedication to find what works best for your body. You need to learn about how hormones work in the body, find other programs people have used with success, and also learn how to properly use supplements (such as how to cleanse properly, what the safest pills and herbs to take are, how pills may interact together, etc.) I researched these things the entire time I did NBE, and I think it really helped me get ahead, and continues to help me as I try to transition to male.
If you're ready for the commitment Natural Breast Enhancement takes, Google forums that are specifically dedicated to NBE (I'm not sure if I'm allowed to post a link to the forums I used, I'm sure you'll find it). There you will find a lot more information than on here. This site is focused on all aspects of gender identity, transition, etc. Obviously it won't contain the same focus of subject as a forum that's entirely NBE.
I wish you the best of luck. Also, look into hypnosis. It sounds silly, but there are free sessions you can download online. When I listened to them, I felt my breasts tingling and swelling. If you're easily entranced, it should work for you as well. There are plenty of natural breast growing methods out there, such as herbs, massage, exercise, etc, so don't get discouraged if one thing doesn't work for you right away. I think the reason people think NBE doesn't work is because they weren't personally successful with it, but more often than not, that just means that whatever they tried wasn't right for their body and, most likely, they gave up after their first (or first few) failed attempts.