Sharing this from another poster - all credit goes to individual companies , and the author. L Hornburger
One thing I will add is rinse rinse rinse and then rinse again - never ever leave shampoo, degreaser or anything in the coat of your cat - because they WILL lick it and while topical wont harm your kitty some things WILL when ingested.
Degreasing a Cat
Degreasing is done before shampooing to remove the majority of oils
from the coat. There are a number of options available depending on the
coat and on personal preference.
1) Dawn dishwashing liquid --
This is cheap and effective for most shorthaired cats, but only seems to
work for less oily persians. It works best if thinned slightly and put
on a wet coat.
2) Top
Performance Degreaser -- This is a bit more, but to me seems to be
better for persians. Again, thin and use on a wet coat.
3)
Davis Degreaser -- This is a gel degreaser, with no coloring and a
pleasant smell. It should NOT be thinned and should be used on a dry
coat. One puts it on and then massages it into the hair all the way to
the skin. It works best if it stands for a few minutes before wetting
the coat. I put it on and then start running the water to the right
temperature. It is very effective for most greasy areas on a persian.
More expensive than the liquid degreasers and the Groomer's Goop, but
not excessively costly if you buy the large jar.
4) Groomer's
Goop -- This is a semi-solid degreaser in a tub. It has to me a
petrochemical smell which I do not like. It does work and some say it
works better than the Davis degreaser, especially on very oily cats.
Again, no thinning, work into the coat, let stand for a minute or two.
This is cheaper than Davis.
5) Les Pooches F&T -- This is
considered the best degreaser by many who show cats. It is expensive
and hard to find. And I can't really say much about it as I just broke
down and ordered my first bottle of it.
When I degrease a cat, I
almost always use Davis first on the chest, behind the ears, the front
legs, and maybe the tail, and then Top Performance second, on the entire
cat.