I think it all depends on which brush you are using.
I used a Salmon with fan jets, rinsed on.
I loved it but it still left spots some of the time.Never had a complaint though or lost a customer and used it for at least 3 months.
Been using Gardiners Supalite mono dual trim for about 4 months, always rinse on, perfect, but it takes longer as only 2 pencils. Next brush I get will be the same again but either a custom made 4 pencil or fans.