It's one thing to blithely talk about the potential for blackmail; actual modern examples in today's "no shame" culture (
https://news.ycombinator.com/item?id=7070045) would be more useful. A
failed attempt at blackmail or worse harms the case you're trying to make.
I could also add "look at the Abscam aftermath" if you think these potential targets are toothless.
And of course I know what adulterated means, I've just never seen that formulation with sex; Google comes up with 4,600 entries, perhaps I'm just behind the times. However I'd use "scandalous", which is in common use, and alliterates.