You're not waiting long enough.
How soon you take it out of the mold depends on a number of things. Oils you used, liquid discount (if any) you used, if the soap gelled or not.
After 24 hours, if it doesn't want to release easily, you can put it in the freezer for a few hours and unmold them frozen.
You can grease your molds, but you are correct that the soap will just saponify the oil you used. If you use mineral oil or vaseline, you'll get an unattractive coating on your soaps.
With use, your molds will develop a patina of sorts making it easier to unmold