Hiding MultiBarLeftButton..i..Flash based on visibility of bar?
 

Basically, I have started using an addon called MainMenuBar_Plugin to hide the MultiBarLeft and MultiBarRight unless I'm hovering over them. I use these bars to stuff unimportant, non-cooldown abilities and profession stuff into. The addon works great at hiding the buttons themselves, but whenever a GCD has finished, each of the buttons affected by the GCD show a "spark" on them.
I believe the spark is called
MultiBarLeftButton1Flash (obviously rinse and repeat for Right and Button 1-12)
What's the best way to prevent these from showing when the bars are hidden, and allow them to show when the bars are shown?

Obviously I could just iterate over all of them and SetAlpha(0) but I think that looks unpolished.

Thanks for any assistance