Have 01 STS Iam going to flush coolant system. I beileve I read some where to add some pellets, question is how many and is the lower hose the proper place to put them? thanks Jim

 

two is all you need and bottom hose will do fine. maker sure it is the organic stuff, not metallic.
Its the same as the Gold Bar's Leak if the dealer dont have it.

You dont really need or should FLUSH unless you got crud and rust in the coolant system. You can simply DRAIN and refill.