Named after demons?

I was on Facebook just now and saw the following claim:

“real names of the demonics are names in most of the characters. You may do your own research.”

Facebook User

I have a deep suspicion that this person’s “research” is just the parroting of what Fr. Ripperger, an otherwise generally reliable source, has said in his talks. Here’s the quotation from one talk I’ve heard:

“One exorcist told me he’s kind of done the footwork. Whether it’s true or not, I don’t know. He said 60% of the names in Harry Potter are actual names of demons that exorcists have booted out of people.”

Fr. Ripperger

So, there are quite a few problems here:

1. He admits he himself is just repeating a claim he’s heard elsewhere from an unnamed source.
2. He admits doesn’t know whether or not it’s true. Personally, I would say that therefore repeating such a claim with no knowledge of its veracity is irresponsible.
3. The claim itself is demonstrably false, even after five minutes of research. Even at a quick glance at the Harry Potter character list, to say that 60% of them are demons is ludicrous as most of the names are fairly ordinary!

Of the more exotic names…

• I can see a few names after star constellations, such as Bellatrix.
• Some names which sound strange to our ears are also names from the Bible. For example, “Silvanus” was the name of one Paul’s companions.
• Rowling seems to have made use of the Dickensian trick of making up a name that applies to someone’s personality. A good example of this is Mundungus which is the same name for an odorous Spanish tobacco.
• Lastly, a handful names like Alecto come from Greek and Roman mythology. However, that doesn’t mean that J.K. Rowling is trying to trick people into worshipping Greek/Roman deities (how would that even work, anyway?). If you’re going to exclude Harry Potter on that charge, you’d also have to throw out Narnia since C.S. Lewis has these Pagan gods appear in Prince Caspian.

So, returning to the original claim… where exactly are these names of demons? Can someone actually point out which characters are named after demons and provide evidence that these names are demonic?