Valve Cover Gasket question

The rubber w/steel cores are definitely the best and my first choice but that's wrong about not being able to reuse cork gaskets. I have them on my car now and have had the covers on and off several times each side and no problem. I do silicone the gasket to the valve cover so it comes off with the cover. Also don't go gonzo crazy on prying them loose when taking them off if using the cork gaskets cause that'll pull the silicone loose.