Well if he works out say twice a day, lets look at this.
Shower when you wake up, shower after A.M. workout, shower after afternoon workout, and maybe squeeze one in before or after sex at night or before bed. OK thats 4 showers minimum, if he has a photo shoot or any kind of meeting that could throw in an extra. So thats 5 showers.
Now for the teethe I personally think it feels great to brush and floss. You dentist tells you after every time you eat. Especially if you a bodybuilder gushing down some high protein meals and shakes. So if he eats say 10 times a day why would that not warrant brushing say 8 times a day and once when you wake up and once when you go to bed ??? No shut the fuck up and go brush your teeth and wash your ass !!!