Just kiddin, i usually use carb cleaner or easy off, but any solvent will do.
that "stuff" is cosmoline, a mixture of oil and wax, generally used for long term storage. Heating it in the oven may help get the "stuff" out of the wood but the kitchen will smell funny for a while
Cosmo is a beeyotch to get off. Look it up, there's tons of good ways to remove it. Dishwasher being one of them. It will make the dishwasher smell funky for a few cycles though. Heat and steam work well too, and there's always solvents, lots of rags and elbow grease. Regardless what method you use, the important thing is that you get it ALL out.