I am testing this myself for a mold I just made. I can tell you more once I try. However I am sure more people will have experience with this and will be able to give better advise.
I made the soap today and plan to unmold tomorrow morning. I would normally wait longer (a couple days); but with 0% superfat (using expired oils), 40% lye concentration and a recipe of 65% of hard oils, it nearly seized even without fragrance. So I think it should be ready tomorrow. I managed to add more oils and liquid to make it pourable. I could feel it was going through gel phase later (the mold is fairly thick). I have also considered putting it in the freezer before removing it.