I completely understand the concern, I certainly would not want to be the poor chap who has to receive the rented garments when they are returned. I have rented a kilt it was about 6 years ago for my brothers wedding, we all wore something underneath, and while it was not a hard rule by the hiring firm it was suggested, for our own health as well as anyone else. Lets face you never really know where these hire kilts have been. Thankfully I no longer need to rent a kilt.