Lana,
I used one tube of it in much the same way that you have described, and I asked much the same questions!
I found, and others have agreed, that getting it on the nipples can cause an unpleasant burning sensation. I was told that the official reason for avoiding nipples/areola is that it bleaches the skin.
I applied it by putting the three pea sized blobs on and then using the middle finger ( only) to rub it in in a C-shaped motion from the centre bottom, up the sides and back across the top. That way you can avoid the nipple.
Finally, I saw no effect at all on my growth and decided that I wouldn't waste any more money on it.
FWIW, Isabelle has found an article somewhere which says that PM actually needs to be processed through the liver anyway, so topical application, either cream or sub-lingual, is not going to work as well as capsules anyway.