I need to ground my teen. How do I block all non-educational internet access to certain devices? I mean no entertainment whatsoever without a password.
No such way.
you could use the routers parental controls but there is no guarantee the sites would be 100% blocked. If at all.
you could do a google search for free and paid software that does what you want but it may be machine specific.
if your child is really bright he/she can access a site just by its dns address (i.e.: 164.123.1? ) and that could overcome the blocks. So find another method of discipline you will save yourself a headache ☹️
Thank you.