Never works. Even if you think it will.

I am glad for rinnosuke finaly being able to SELL "some other" books.
Even in the case he will be paid in peaches, he still gets paid.

Of course, his scanner will fail on the ONE thing you're trying to avoid attention to and he will inevitably call out on the PA for a pricecheck on it announcing to everyone around that what was the thing you were trying to sneak through. It's a checkout counter...it's inevitable! Don't argue with me that he doesn't have a scanner or PA or even that there probably aren't any other customers around...it's going to happen...

I've done this before, grab a few random mags, shuffle a copy of porn in between, hope the cashier is a dude, and that the people around you/behind hind you don't try to get too curious. Otherwise wait around at the magazine rack until there is almost no one at the cash register. Man the good old days, when porn was bought in hard copies.