I go back and forth and have only just realized that right now!

At this point, while the rule might not have officially changed, the language might be adopting the "of," since you're right in saying that it's pretty common.

As state in the previous comments, one is a verb and the other is a noun. You just need be sure that you are pronouncing each term correctly to show the difference.

to advo-KATE = verb
an advo-KIT = not

(Of course, people's accents might be slightly different... but that's how they each sound in my head!)