I took care of my elderly Dad for years before he passed, bodily fluids, esp, urine, is very strong with older adults, and those who are sick. It IS a challenge to get that smell out. I used Borax and a long soak, about an hour. Switching to top shelf detergent helped a lot also. I line dried sheets, and bedding, and that aided as well, but I realize not everyone can do that. Eliminate Gain and get Persil or Tide if they can handle that with no allergies, or reaction. If someone else is doing the laundry in the household they might be setting the stains and odors in the fabrics, think it has to be laundered on a consistent basis the same way. Hopefully no one is using cold water.
Barry
Barry