I've recently had several jerry-cans of oil (awaiting disposal) topple over in the attached garage, and several rooms following influx of water following heavy rain. After the water level receded the floor is left with a thin layer of burnt oil.
Various sites on the net recommend using sawdust, baking soda etc. I'm talking close to 800sq.ft of area split into several levels with a step between different levels.
The question I have to ask, therefore, must be obvious now. How does one clean large volumes of burnt oil spilt distributed by water over cement, and stone floors?
EDIT: Nature giveth, and Nature taketh away. Another cloudburst, this time over 100mm of rain in a couple of hours, and muddy waters found their way indoors again. Now the waters have receded, and almost all the oil is replaced with a thin layer of mud. Hopefully washing with water will get rid of the most of it.