enigmatic puzzle - Neurotic frogs ought to relax in mud baths

What is the hidden message in this advertisement?

Neurotic Frogs Ought To Relax In Mud Baths!

Perpendicular lounging calms. A frog, a mud cap... bliss! Wallowing generates happiness. Amphibian spa isn't expensive--seventy dollars--cheap! That's not a large expense from any discerning frog's money, unlike Super 8.

Everyone--frogs, toads, newts, and salamanders! Get a wonderful shiatsu, or receive an other kind. Masseuses are here today! Invite a fiancée, supervisor, roommate, niece: all welcomed!

You simply never believed these possibilities; they're (I swear) absolute truth! The Montgomery Amphibian Salon! Come luxuriate today!

Hint 1:

Notice that the last word in a sentence never contains italics.

Hint 2:

Frogs, toads, or newts--makes no difference. But dogs or horses are a different story.

Hint 3:

"Tadpoles" must be accompanied at all times. Our company policy states: "Business standards allow only adult amphibians."

Hint 4:

Eggs and tadpoles are quite different, of course. However, we don't discriminate among eggs, tadpoles, or even tadpoles. On the other hand, there's a big difference between tadpoles and polliwogs.

Answer

The main idea:

Convert each word: If not italicized, to word length, if italicized, then irrespective of number of italics, either to 1, if the length is odd, or 2, if length is even. Then pair each italicized to the right side word, and read in A1Z26.

The entire message reads:

Hello, my name is Inigo Montoya. You killed my father. Prepare to die.

The #3 hint reads:

Hint

Puzzle is a, ... I can't. I puzzlingly ... I didn't. Don't ... I swear.

Thanks to @Verence and @Wu33o for having time do decrypt the message. It took me around 13+ hours to solve, ended up waking up all night, and the fourth hint reduced too many possibilities.