Where I lived the paytv encryption just removed the sync signals and audio and by finetuning the TV you could get a fairly clean black and white picture. It sounds similar to Discret 11 but it wasn't quite the same.

Only with a major scene change (eg day to night) this would need retuning. And this type of content didn't really do that, as most of these movies take place in the same bedroom :) so it was not a bad way to watch it.