:P
I would consider a ponytail professional
-I've never tried a dry shampoo (Thankyou google, I now know what they are)

I found that when I was carrying everything with me I tended to occaisionally forget stuff

Make sure you have a supply of emergency undergarments
Yeah.. I needed them
and did I have any emergency supplies? No.

Wet Towel: I bought a Large camping Towel - Quick Drying, anti-bacterial, microfibre, I toss it in a sink - scrub it a little with some soap flakes, wring it out and then hang it up mid-week and have a dry and clean towel the next day
and most importantly it rolls down nice and small so I can take it home for a proper wash without having to bring a larger bag with me

It's dry by the time I'm dressed most days - if it's not dry I clip it onto a hanger and hang it behind the door in the emergency stairwell
And well.. to be honest I do that when it's dry too
Mine came with a mesh bag - so if it falls or anything I'm not stressing too much about it getting dirty or smelly