saw dust! Get as much water/oil out as you can and then go to a millwork place and get a couple of bags of sawdust. drop it in the
bilge and let it sit for at least a few days. It will suck ALL the
oil out! If you can get softwood saw dust I think that would
work best!
Last summer we replaced our old
Perkins 4-154 that must have leaked oil for decades. When we cut out the
engine beds we found oil sludge in places I wouldn't expect, but in the process of rebuilding the
engine room we created alot of sawdust and as we were only working weekends we forgot and left the sawdust in the bilges and stuck to the sides of the
keel. When we came back the following weekend the sawdust was full of the oil and the
fiberglass looked brand new!