I had a nursing instructor who swore by using nipple stimulation to start labor as well as sex.
I'm going with nah. I see a lot of women trying to self induce to avoid medical intervention but often the method they chose is not 'natural' and they still end up needing medical intervention. But each to their own. My dr never recommends it and I don't believe in it but can appreciate that some women feel its right for their body and baby.
I know few people that they actually worked for though.
Most methods are considered safe, however do have slight risks (just like anything else). The real question is, do they work? If your body isn't ready than nothing you do will work. If your body is ready these methods may help things along although it's not proven as to whether or not it's the induction method or just your body's natural process that puts you into labor. There are probably several occasions where it helps speed things along and several where it's simply coincidental.
It depends on what they are doing. However, no matter what you try, nothing will work if your body is not already in the process. There are some methods that can cause baby stress. Other ways can cause mom extreme discomfort. Hospital inductions don't even work when your body isn't ready. I'm not sure why people are so convinced r hey can make it happen in their own.
Just trust your body and let baby come when he's ready. That really is best.