How to get stink out of tent?

Welp, it's happened. My trusty REI Half Dome 2 is getting a bit stinky. I never cared when it was my dad's tents but now that it's happening to my workhorse (for husband/wife trips at least) I wanna get RID of it.

REI says there's something called Mirazyme I can use. Is there something I can make at home to do this? It's not visibly mildewy anywhere, how do I target the problem, or is there just a rinse that I can dunk the whole tent in?

Thanks!