Yeah, just wash with soap and water regularly. If you find soap irritates you, use baby lotion or sensitive soap or alike.
Usually if you leave semen to settle it starts to stink and sometimes we can release "pre-cvm" when we're turned on or in the night, which can contribute to that odd smell down there.
Personally, I wash myself down there in the shower, before sex and after sex, and spray deoderant to stop myself getting sweaty.
If a girl's experiences of oral sex are clean and fresh, she'll be happy to do it more often! It's worth the effort!