There's nothing hamfisted about monitoring what other adults say to teens (and younger) when alone. It falls under basic supervision of minors, in order to prevent abuse.
Including abuse that abusers try to shoehorn in under the guise of noble cause. For example, like sexual grooming, cultic induction, political radicalization, etc.
Anything that anyone can say to a child, can be said to an adult. I mean that in two fashions.
The first is that it can be said in the presence of a guardian. If it can't be, that's a red flag for abusive and grooming behavior. Children have what is known as "guardians" for a reason. They are charged with making decisions for the child until that child is an adult. Which includes making decisions about steering them around abusive adults. Trying to circumvent that firewall is red flag behavior. Everyone who aims to do this should know how they are framing themselves. If an adult has something to say to children that is outside of the known school curriculum, then there is zero reason that it can't be said to their guardian at the same time.
The second fashion that I mean the assertion that "anything that anyone can say to a child, can be said to an adult" is the following:
If someone believes that what a parent teaches a child is misguided, then there is no reason whatsoever that their alternate presentation of facts cannot wait until the child is an adult. Assuming that their guardian wants to sheild them from that alternative view.
Needing to present alternative views to a child, instead of an adult who is more capable of wieghing what they say, falls in the same category of suspicious red flag behavior.
You may have appreciated the alternative views that you sought out as a child, but the truth is that you circumvented your parent's guardianship. And if your current views are valid or more valid, then they would have remained so once presented to you as an adult.