Actually, the stealth continues in many different areas. You may receive a bible study without knowing it. But, even if you ask them an outright question on several subjects, they will lie to you until you are hooked. Then you get the full picture when it's too late. Consider:
Ask a witness: Are you here to convert me? They will say "no", we are doing a Bible educational work. This is a lie. They are there to convert you.
Ask a witness: Are JWs the only ones who will survive armageddon? They will say "no", it is up to God to decide. This is a lie. What they don't tell you is that they know for a fact that God will decide to save only JWs, and even then, only the really good ones.
Ask a witness: Am I allowed to vote or take a blood transfusion? They will say it is up to every person's concience. This is a lie. What they don't tell you is that, although it is up to your individual concience, your individual concience bloody well better tell you not to do it.
Ask a witness: Are persons disfellowshipped for voting or taking blood transfusions? They will say "no". This is a lie. They believe that if you do these things, you are indicating that you are no longer a Witness, and you will be shunned as disassociated, which is exactly the same as disfellowshipping.
So, the Witnesses have a long history of stealth when it comes to converting people. They have to be stealthy. If they told people outright what they believed and what they were trying to do, before that person became committed, they would never convert anyone.