Seems my old fashioned use of the English language was caught again in my reply above:
" it puts down a cleaning solution, scrubs and ***** up most of the liquid and dirt."
The sensored word is the one used to describe drawing a liquid up through a straw with one's mouth. So what to do, replace "suc.. up" with withdraw? I'll bet the rug cleaner user manual used the "s" word. Guess the site can't be too careful.
Reading and learning, I now understand this post to ask the question of how to prevent infection from spreading the underlying disease - I was focusing in error on how to clean. .
Clostridium difficile (C. diff) is present in the intestinal tracts of most human beings. It's only when it starts to proliferate, usually from taking an antibiotic that kills off too much of the good intestinal bacteria, that it becomes a problem. It's usually pretty mild in humans but it can be a problem if it's not taken care of.
As far as him cleaning up after his dogs, common sense with regard to handling dog waste will probably be all he needs to employ. Thorough, regular washing of the hands with an antibacterial soap after handling the waste will ensure that nothing came into contact with the hands themselves. As far as the carpet goes, most carpeting today is able to tolerate a bleach/water mixture without any adverse effects. Mix up some at a ratio of 1 part bleach to 8 parts water and try spraying the carpet somewhere that it can't be seen. It should remove the stain and any bacteria from the carpet without harming the carpet itself.
Also, Febreze makes an antimicrobial fabric/carpet freshener that you can spray on the spots after they are cleaned to make them smell fresher and actually BE cleaner.
It would also be a good idea to buy some rubber gloves for him to wear while cleaning up, even though the bleach/water solution and the Febreze are both anti-bacterial/anti-microbial.
Ghilly
I use a mixture of 1/4 cup alcohol, 1/4 cup vinegar, and 1 cup water in a squirt bottle for accidents from my cats, it seems to work pretty good. You might want to test it on a small spot first, but I've never found it to harm my rugs or furniture.
I know nothing about the "c-diff", is that important?
What kind of accidents, just urine? This has the problem that it soaks in.
I use a home appliance to shampoo rugs, it puts down a cleaning solution, scrubs and ***** up most of the liquid and dirt. I always use a cleaner that claims to take out pet "smells". Our dog doesn't have an accidents but I think dog urine can be successfully cleaned well enough to remove sight and smell - no sure about germs.
The urine of a male cat is another matter.
I admittedly am no expert on c-diff, but I do know the strains that infect dogs and cats typically do not infect humans and vice versa. Unless your dogs have been drinking out of the toilet, I doubt they are carrying the bacteria. If you want to know for certain, ask your vet to do a test for it. Is it possible the dogs are having accidents in the house because your father is too sick to let them out regularly?