I use a Gillette Sensor cartridge razor, and have for years. From what I understand, the most likely cause for failure is/will be the plastic parts which hold the cartridge in place. The head of my razor is coated with shaving cream scrum - again. In the past I have used hot water and an old toothbrush to scrub it clean, but this isn't getting inside the mechanism. Is there a solution/product that will remove the scum without harming the plastic mechanism? Anyone have any experience/recommendations? Thanks, John