What's the meaning of 擦脸? Neither mdbg.net nor Yellowpage nor Pleco seem to know this word, though it seems to be common. It stumbled over it in the first HSK4 mock test:


  这个节目我一直在看,它介绍了很多生活中的小知识,包括怎样选择牙 膏,擦脸应该用什么毛巾,怎样远离皮肤病等等。很多以前我没有注意到的 问题,现在通过它了解了不少。


I thought it must be to clean one's face or something similar. A web result suggests you can use Vaseline for it, so it's focus might be more on grooming rather than cleaning?

Anyway, what does this mean and why don't dictionaries know that? Is it very colloquial?
擦脸 is not a single word but a verb (擦 cā: wipe) plus a noun (脸 liǎn: face) that serves as an object. "擦脸应该用什么毛巾" means "what kind of towel you should use to wipe your face [dry]".