It really isn't a hyperbole. This chord in the final scene of Strauss' Salome Op.54 has been called "the most sickening chord in all opera". One of my teachers constantly recalls the moment he'd heard this chord live and it had literally shocked him out of his sleep. I myself recently went to watch Salome in Paris and I can testify to the incredibly horrifying effect this chord alone can produce.
Of course, that's probably what Strauss had wanted a cacophonic representation of lust, revulsion, horror and doom all at once. Salome kisses Jochanaan's severed head and the 2hour long opera reaches its greatest climax. Essentially the bottom harmony of the chord could be replaced with the V7 chord and the melody would make sense in that context, the genius is combining that same melody with another chord that also has an attraction strong enough towards the I chord the Italian 6 in this case. A and G both resolve outwards to the G sharp in the resolution and the C sharp is a common tone.
A few leitmotifs are used in this final scene: the "kiss" motif which is played whenever Salome expresses her desire to kiss Jochanaan, the "desire" motif which is a rather romantic descent of four notes and Salome's leitmotif itself which is played by the clarinet at the very beginning of the opera a light, graceful flourish.

Recording (Stratas, Vienna Philharmonic):    • Strauss Salome final scene pt 3 of 3