Benne means butter, Alankara means decoration. Lord Ganesha is decorated beautifully with butter. Cow denotes Kamadhenu(Wish fulfilling celestial cow). When we do Alankara to Lord Ganesha with the butter from cow's milk, all the obstacles in our life is removed and our noble wishes are fulfilled. If you feel someone in your family is very harsh towards you. To make their mind and speech soft and satvik as a butter, you can get this pooja done in their name and star. Butter will be sent to you as prasadam.