hands down the best product on the market for cleaning up oil & grease is called Oil Eater. it is an enzyme that breaks down oil into a water soluble form. it's biodegradable & nonpoisonous.
spray it on, scrub a tad, let it sit, & rinse it off. nothing like it.
http://www.amazon.com/Oil-Eater-AOD1G35437-Cleaner-Degreaser/dp/B000EALHHG