There were lots of stuff I didn't use, but they all had a purpose behind them.
One example was the swimsuit. We didn't go swimming, but it was used for showering if you had the time to put it on and if you felt uncomfortable with showering with other people (girls had seperate stalls if I was told correctly, boys just have a room with showerheads)
I didn't use athletic compression shorts, or bathrobe, to name a few, but again, these all have a purpose behind them. I just never found the time to be able to use them.