I shower both in the morning and at night. I have started doing this just 2 weeks ago. Haven't noticed a difference yet but it's still early.
Think about it: In the morning, you've been lying down under a sheet/blanket for 7 hours straight. You're probably sweaty in places. Which is why you shower in the morning. At night, you've been walking/sitting/running (whatever) for 12 hours straight. You need a good cleaning again. At night, I don't do anything fancy like wash my hair or shave - I just jump in, wash, and jump out. 5 minutes tops. And I feel better.