I found it best to have everyone on my team drink the Cologne Neutralizer. Then you DPS down Hummel first (who uses the purple/perfume stuff that hurts a little bit) and stay out of the easier to see purple clouds Frye throws down. Ignore the harder to see green clouds.

One other thing - I went ahead and got ilvl 346 necks for all my level 80s too. If you are in SFK, remove a toon, add an 80, they can port in, help kill the boss, pick up, and wear the neck. Note that this was before today's patch. I assume it still works, but you know Blizzard - they like to change things that work well.