Intermittent bladder catheterization is done by many people for a variety of urinary tract problems. It is generally done using "clean technique." This means that not all bacteria (germs) are kept from coming into contact with the person being catheterized.
Sometimes "sterile technique" is used, which means all equipment, including gloves, is sterile.
No matter if you use “clean technique” or “sterile technique,” if you re-use catheters they need to be cleaned between uses.