Glow by Lady E

I have recently rediscovered my Etude House beauty sponge. I stopped using it because I didn’t have the time to wash it after using. I preferred my disposable sponges over it. Now that I have more time on my hands, I use it more often. I do have a problem though. It’s so hard to clean! I’ve had this problem since the beginning. I’ve tried cleaning it with Ivory soap and my Etude House makeup remover (Bubble Oil, I think) but it still has foundation stains all over. I’d like to continue using it (as it’s not necessarily cheap)  but the stains are really bothering me. If you have a similar product, I’d like to know how you clean it. Thank you ladies!