grub
Occasional Visitor
Doesn't work for me at all. I made a short video showing what happens to me on my Android devices. Sorry for the bad camera work but hopefully it's visible enough to get my point across on my experience.
A lot of apps, including some YouTube implementations, hard code in a default DNS. Often these are 8.8.8.8. You should block all outgoing DNS from everything but your DNS device.
Our Sony TV was doing this.