Things that come into contact with the upper body must not come into contact with the lower body. Great care is taken to avoid allowing unclean things to enter the body. Food improperly cooked or dishes and utensils improperly cleaned must not be taken into the mouth. Even amongst themselves contemporary Roma in Eastern Europe will share a pipe but will wrap their hand around the pipe stem and draw smoke through the fist. The cat is an especially unpopular animal because it licks itself, taking dirt from the outside to the inside.
Bad luck can also contaminate.
Trouble with the authorities, for example, can bring Gadje scrutiny to the entire clan. Other regulations seem so commonplace we take them for granted. Men's and women's clothing and upper and lower body clothing are washed separately. Pets are dirty animals and are never allowed to live in the house. They must certainly never be allowed to eat out the dishes that people use.