When I took my first class with Tom Sheppard (many moons ago), he told us (only half jokingly) that the first and wisest thing we do while the client is not looking, is tear the sticker and dispose.
Client ignorance at times is bliss.
Most client are intelligent and if you explain clearly it works well and most of the time they will go along.
I offer to do a dry cleaning with the clear explanation of what it really means (residue, products etc.) and cleaning results to be expected. And if they still choose a "dry" method, a written and signed client's consent that if the results are not to their liking and I have to do it again, they'll fully pay for a second cleaning.
I do test, if needed and practical. Though we all know that in most circumstances a perfect testing is not possible. It may require two trips and will not be very cost effective. For me as an O/O it means either making half the profit which I am not willing to do, or close to twice the price, which most clients are not willing to accept. So there's always a certain risk involved, which in most cases and experience, is close to negligible.
One instructor that I know said (before he became in instructor) that in reality, one can skip the tests altogether and clean right away as most fabrics will be just fine. And the one sofa you'll have to buy every four years will be more than paid for with all the time savings of not wasting time on testing. He was absolutely right (especially if you don't serve the super wealthy that buy only designer sofas).
Now that he's an instructor, he vehemently denies that sage advise.
P.S. Hey, Jim, can I call you for that test advise?