I don't understand this sentence

Hey guys

I'm a huge Charles Bukowski fan and i'm reading his book "Notes of a dirty old man" at the moment and i have some problems understanding this sentence:

...took the lather and the brush and began dabbing at the string and knobs."

Could someone explain this to me in an easy way of saying this?

Thank you so much

I would need more context. Just from that, it sounds like someone is preparing to shave off his pubic hair.