Short story

Years ago I used to have o small store with plumbing and heating materials. At the entrance was exposed toilets, lavatories, pedestals and floor-wall tiles. It was at the end of the day when a new customer step inside. After a short look he wiped one of the lavatory and I considered is time to approach and asking him what he is looking for. He said he wants to buy all what is necessary for one bathroom from my store. After he paid I ask him why he wiped the lavatory and he said it was the only store in the city where was not dust on the items exposed! And more than that he said if somebody invite you to eat in his house, before to do that is better for you to ask the permission to use the bathroom and if that one is clean you can eat if not no, because that will show you the dimension of the cleanest of that house. So, be aware!