No it won't. This won't be any more effective than the DMCA was at stamping out piracy. Porn sites will get scraped, bundled, and torrented.

If the goal is to reduce the profits that porn makes, it will have some impact. If the goal is to actually block underage exposure? Not a chance in hell it works.

And pretending it will work just turns it into an anti-anonymity arms race until you need a government-controlled camera watching you to open an IP connection and that still won't work.