I want to know the answer to the following question:
Bell used his own design in all public demonstrations and what?
All the background I'm provided with is that "Although Bell was, and still is, accused of stealing the telephone from Gray, Bell used Gray's water transmitter design only after Bell's patent had been granted, and only as a proof of concept scientific experiment, to prove to his own satisfaction that intelligible "articulate speech" (Bell's words) could be electrically transmitted.". Is that enough to answer the question?
Answer: no