[Pansy-Mae]

Your real problem is actually getting anything to go right through the skin rather than simply dry in the top layers...the skin is designed to keep the inside and outside separate, which it is remarkably good at doing!! Most things have a molecular size and structure which will not allow them to penetrate the skin to the point of allowing it to be absorbed by the bloodstream.
Most of the pparent effects of rubbing things on the boobs are really only massaging effects and improving the local blood supply
Thats what carrier creams are for.