Technically, although never expressly stated on the show, they could be using supplies pilfered from the luggage of the deceased. Therefore, they could be using shampoo, toiletries, etc. Same with clothes, although it is amazing that all the clothes fit perfectly.

The men always manage to shave every once in a while, too.

I've loved the premise of the show, although with the exploration of the "bunker" the writers of the show seem to be boxing themselves into a corner - but then they seemed to be doing that all along.

Its nice to see the survivors from the tail section.

See ya' in the next life, brother--

Freightdawg