Lavender Oil. One of the essential oils that have major benefits to soothe the muscles and to improve the blood flow is lavender oil. This can be mixed with a little carrier oil like olive oil because of its high concentration. Use this on the penis to improve its strength.
Any mild oil which suits to baby. Which dose not cause red spots / rash on the skin. Massage helps for mental bonding. So it is to be done by parents. If no oil suits, it is ok with no massage also.