I need a Catholic priest and some Holy Water

My brother in law and siste rin law are going through some rough times with a child, and guess whose there to help-- the SUPER GRANDPARENTS!
They have effectively butted their overly long noses into a business which had nothing to do with them.
And, as if that wasn't bad enough, they are giving parenting advice.
Excuse me? But do you even speak to one of your sons? And how hard are you working on alienating the other?
They are the worst examples of parents ever. Really. They are in textbooks. Look under bad parenting, and you'll see my in laws.
They've never even seen my two youngest children, and haven't seen Bug since he was a year old. But they claim to love them. From a distance, thankfully.
Wonderful examples of grandparent and parents that they are, their family can't stand to be around them. Mention a visit and watch how fast we all make for the door. And it gets dirty, the biting, scratching, and hair pulling. None of us want to be trapped with them.
But they announce loudly and frequently what great parents they are.
But I guess you can imagine yourself to be anything you want, and if you wish and believe hard enough, Tinkerbell might just live. Clap really hard everyone!
And I'm the bloody King of Siam.
My in laws are just plain evil. Complete with horns and a pitch fork. They even have the members cards to prove it.
So I'm calling for a priest and a gallon, no a truckload, of Holy Water.
"Satan! Be gone!"
Damn. They're still here. Well, on to the next idea.
Sulfuric acid and a deep hole in the woods.