You can do that as long as nothing is chlorinated. Examples, carb cleaner, chlorinated brake cleaner, Anti-freeze, chlorinated solvent...... I'm not sure if kerosene is acceptable or not....gasoline is a gray area as it's extremely volatile and most places don't care to have a bomb under the parking lot.
Hazardous waste disposal is probably the correct thing to do if you have large quantities. I know Douglas county has three every year, one in Parker, one in HR and one in Castle Rock. Small quantities either evaporate or mix in with your old oil. Used coolant should be taken to hazardous waste disposal as well.