Ah, you are partially right and partially wrong in your assumptions.  Yes, if it is a non-hazardous material absorbed onto the "oil dry" and the resultant mix "seems" dry to the sight and touch, then it can be landfilled as regular trash (pure silicone will meet this test).  BUT, the hydrocarbons you mentioned will 1)never really truely dry, 2)are cumbustible fluids which is an EPA ban for any landfill, 3)will come off the "oil dry" and cause a sheen on any water surface which is illegal to cause and 4)will most likely not pass the EPA tests for toxicity since they come into contact with all kinds of metals during their use, some of which are banned from landfills at 0.01% and lower, for fear of leaching to ground waters.

Your best option is to have your cutting oil supplier do an exchange of your fluids where they re-cycle and clean them up for re-use.  If you are large enough organization or belong to an association, you can re-cycle your own.  In some locations, you can use it as and EPA approved industrial fuel for a furnace or incineration.  Check your local yellow pages for categories for waste, oil, recycling, industrial cleaners, industrial disposal.  Then actually visit the process site to verify it is done correctly.  Once you buy it, by EPA rules, you are fully responsible for it until it is "neutralized" or no longer exists.

Good luck.

We recycle/ reclaim the bulk of our materials, however despite our best efforts we end up with some material on the floor which must be cleaned up. Either oil dry, pads or a mop to clean the floor.