One pair on, one pair off and one pair in the wash !
At least one weeks wear was the rule when I joined over 40 years ago.
The laundry took one week and it was the rule that the one in the locker was of pristine condition.
And as for sheets - Top sheet goes on the bottom and the bottom sheet goes in the laundry.
'We knew how to whinge but we kept it in the NAAFI bar.'