"I don't like silk underwear. They don't do the job, you know?"

In this quote, Matt LeBlanc is expressing his dislike for silk underclothing. He believes that silk underwear does not provide the necessary support and convenience that other types of underwear do. This might be due to the fact that silk is a thin product that does not supply sufficient protection or assistance for the body. It could also be because silk is not as breathable as other materials, making it uncomfortable to wear. LeBlanc's viewpoint is that silk underclothing does not do the job, suggesting it does not provide the necessary support and comfort that other kinds of underclothing do. This opinion is most likely shared by many people who have actually attempted wearing silk underclothing and found it to be uneasy.