'how nauseating' is a correct and usable phrase in written English.
You can use it to express disgust, revulsion, or distaste at something. For example, "I saw the way he was treating her; how nauseating!".
My best friend and I had no real idea how nauseating the film would be; we were young and, hey, bloody heck, we were foolish.
He would do this not in hopes of changing anything, but to illustrate how nauseating these pretend elections are.
It is astonishing how peculiar high G loads can make a person look and sound, and how nauseating high-stress aerial maneuvering quickly becomes.
And I'll devour just about any fast food, regardless of how nauseating it might seem to someone classier than I am.
I posit that networking sites only exist for two purposes: blatant self-promotion (which makes sense for those who are already famous and is completely understandable, no matter how nauseating it may be) and ego-stroking.
For the early crowd that finds that description of the late-night scene nauseating, how about a calm drink with a view at the Mandarin Oriental's Lobby Lounge, on the 35th floor overlooking the southern reaches of Central Park.
These prices attract the derision of some amateur photographers, who see them as proof that Leica has sold out – abandoned the business of serious photography for the universe of luxury goods dominated by Louis Vuitton, Breitling et al; the world of the Financial Times's nauseating "How to Spend It" supplement.
The abundance of space the man must have enjoyed on this luxury floor is nauseating considering how much the citizens of East Germany suffered under his watchful eye.
That's why it's impossible to gauge the full range of our responses to the Islamic State atrocities without apprehending the nauseating disjunction between how connected we are and how impotent.
To the Editor: Your article is a nauseating reminder of how lobbyists and entrenched interests can influence what would otherwise be common-sense government policy.
