Try to use oil to clean it
If you can not find a good way to clean it: Step one: Use water absorbent towel to repeatedly rub (water absorbent towels are sold in supermarket, sticked on the brush added with water to brush until it is clean; step two, such as OMO: Spray perfume on that part (if you have no perfume, then I'd like to give you a more operational advice. (this must be repeated several times before the bubble is totally removed) step three: Use the hair dryer to dry that part. Step four, until it almost half dry, that kind of towel that can dry hair is also a good choice): Use good quality washing powder
