Plugin Help WorldGuard Greetings - Help Needed

I have "immersive" greetings set up in several areas of my world that note a small observation about the regions as players pass through them. I love them, and the players love them, but there are times when they can be a little spammy and annoying. If a player is moving in and out of a public building that has a greeting, it can be more immersion breaking that anything.

The smell of mildew fills your nostrils.
The smell of mildew fills your nostrils.
The smell of mildew fills your nostrils.
[Global] Bobbybuttcakes: where does i get apples
The smell of mildew fills your nostrils.
[Global] JimmyRustle: from the tree ya dingus
The smell of mildew fills your nostrils.
The smell of mildew fills your nostrils.

So with that obnoxious example out of the way, I'm hoping perhaps there is a way that I can put some sort of cooldown on this function, so the same greeting won't repeat more than once every 30 seconds or so?

Any help is appreciated. It would help us out so much.