When there is gum on clothes, I put it in a plastic bag and place it in the freezer overnight, the next day the gum is so hard that you can easily remove it with your nails with large pieces.
I had a terrible gum stain in my favorite skirt. I had put him in the freezer, but he was already so far revoked this did not help. I consulted granny gives advice but didn't believe the peanut butter tip. I first tried it with butter, but that did not help. Then anyway peanut butter, worse could it not become. And you know what? All that gum stain there's just went out.