If soap cleans by removing sebum oil from your skin, and the palms of your hands don’t have sebaceous glands, which are the glands that produce sebum oil, does that mean soap never cleans the palms of your hands? If soap still cleans the palms of your hands, how does that work despite the absence of sebum oil of the palms of your hands?
If soap cleans by removing skin oil & your palms don't have oil glands, does soap never clean palms?
Sebum is produced mostly in the scalp, face and hairy regions, and requires a detergent to wash away effectively. This is why washing your hair with soap leaves a gooey mess.
Soap works by binding to both a water molecule and a dirt (including oil) molecule, to carry it away. The small amount of sebum exuded by the body skin doesn’t change this much, even though it is resistant to ordinary soap. Most people get dirty, slightly oily palms; there you go.
First of all, when you wash, it is not really the soap that cleans you, it is the water that cleans you and carries away the dirt. The only problem is that grease or oil does not naturally mix with water, and tends to stick to the skin (or whatever else you may be washing) and so not get carried away by the water. Soap or detergent serves to loosen any grease or oil on your skin (including the oil it naturally produces) and any other dirt stuck in that grease or oil, so that the water can carry it away.
So, if the palms of your hands were completely grease and oil free, you would not need any soap to wash them. Just water would be sufficient to remove any non-greasy dirt that might be there. However, it would be inconvenient and pointless to try to avoid getting soap on your palms when you are soap-washing other parts of your skin, that do get naturally greasy.
Anyway, in practice there will usually be some grease and/or oil on your palms. Just because they do not produce oil, it does not follow that oil cannot get there. It may have spread there from other areas of your skin that do produce oil, or it may be a component of whatever the dirt is that has got on you. In that case, soap will help with getting them clean.
Didn’t you ever watch the “Beverly Hillbillies”? Granny used to make her own soap by cooking up a batch of lye and hog fat in a big vat. Soap was the third greatest discovery of our cavemen ancestors (after sex and fire).
Palms get oily because (1) eccrine (sweat) glands do secrete some lipids, (2) people touch their hair, faces, and other skin, and pick up oil that way, and (3) daily tasks like eating and working usually involve contact with oily substances.