Cats should keep themselves clean. Generally the only exceptions are when a cat is very ill.
Are you saying that your friend's cats are the hairless type - such as the Sphynx? Or does your friend shave her cats or have them shaved?
I don't know why a cat would have such an odor. I've never encountered anything like that.
As to bathing a cat, I would not bath a cat unless it got into a lot of something really messy like paint or oil or a skunk.
Here is how I tell people to bath a cat:
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Steps to follow to wash a cat:
1) Insure an adequate supply of blood which is compatible with your blood type. I am AB+ and can receive any positive type - A, B, AB, O. If you don't know your blood type, ask you doctor to run a test and let you know. I would suggest having at least 3 units of blood standing by before you begin the cat's bath.
2) Get a hockey goalie's mask to reduce the amount of damage done to your face while you wash the cat.
3) Wear the thickest gloves you can find which still give you some dexterity.
4) Get a welder's jacket, it will provide some protection to your chest and abdominal areas.
5) Put up warning barriers to keep innocent bystanders away from the scene of the action in order to avoid injury to said innocent bystanders.
6) Remove everything from the counter top, surrounding the sink to be used, to reduce breakage.
7) Insure that someone is standing by, safely outside the action area, who can administer first aid - to you, such as the application of tourniquets to stem blood flow - as needed.
8) Adjust the water temperature to about 90 degree Fahrenheit.
9) Pick up the cat, hold at arms length and put it in the sink. It is at this point that you want your first aid person paying attention to the action.
10) Wet down the cat, avoiding the face. Again, your first aider should be alert during this procedure.
11) Apply the shampoo and lather well stay way from the face and ears. Disregard the red color to the shampoo draining off the cat, that's just your blood, the cat is okay.
12) Rinse off the shampoo, again, the cat is fine, the red is your blood, not the cat's.
13) Repeat steps 9 through 11 - if you are still able to stand and are not dizzy from blood loss.
14) Dry the cat well. You can use a hair dryer set on low if you don't hold it on the cat very long. Move the air flow on and off the cat. You can also dry the cat fairly well with a towel. You will want to use an old towel since it is difficult to get blood stains out of cloth.
15) Go to an emergency room to have them suture the deep scraps and bites you've picked up. You may need that extra blood at this point. It is not wise to drive yourself to the emergency room if you are in the least bit dizzy from blood loss. Have someone take you or call for an ambulance.
You should be aware that some medical insurance plans will not pay for self inflicted damage, and injuries incurred while bathing a cat are generally considered to be self inflicted.
We once tried to bath two 9 week old kittens and the only thing we accomplished was to learn that they had all 19 of their claws - 10 front, 9 in the back.
There is nothing that would get me to bath a cat. Even if the cat was sprayed by a skunk I'd not want to wash them. If I had to, I'd want to sedate them first