There is an AC cleaner kit you can buy from the dealership parts center. It costs about $21. plus tax. pretty easy to do. I just did mine last weekend and the ac feels stronger and smells fresh. Costs about $79. for the dealer to do it. Atleast locally
this is a 2 can process 1 large, 1 small:
The large can is a foam cleaner that comes with a hose attachement you put in the ac drain hose, (located on the passenger side under the hood near the bottom little black hose about 3" can't miss it).
attach and spray the can in the drain hose, after about 10 minutes the foam liquafies and the gunk inside will come out.
The small can you spray in the cowl vents while the AC is on. These are the vents that are under the hood near the window. There should be 1 on eachside and a center one as well. Make sure the ac is on high and letting theoutside air in.
That should clear up any smell and clean out the unit.