and I can tell you that maybe you need to shop around for another groomer. Every dog has a certain type of skin and coat...even two dogs from the same breed and litter may have different shampoo needs.
Using one flea shampoo (or one of any type) is not good.
Flea shampoo is very drying for the skin, not matter how much "shine" is on the label, lol. It sounds like this groomer does not want to spend the $$ on different products.
I use one main manufacturer, but I have over 15 different types of their shampoos in my grooming shop for the different coat types and skin problems on the clients I groom.
As for the slicker brush, it is NOT a problem to use it on a yorkie. I know that the TV show said to use a pin brush...and a pin brush is good, but it is not a bad thing to use a slicker. It will not pull out your dogs hair. In my grooming videos I recommend a slicker, but also show a pin brush and a boars hair bristle brush too.
If the slicker is a good one (Oscar Frank's Universal Slicker, made in Germany, inexpensive) it will not cause the damage. Almost every groomer in America uses this brush on most of the breeds of "pets" that they groom.
It is a safer choice for inexperienced pet owners to use, and that is why I recommend it to pet owners in my grooming DVD's. If, which ar estrictly for pets, not show dogs. If you have a show dog (like the dogs in the TV show) then you would strictly use a pin brush. The Old English Sheep dogs on the TV show were owned by a show dog owner/breeder/judge.
Slickers can stretch the fur and cause "slpit ends" but it will not rip the hair out.
Sue & Cricket