What are cocoa hulls best used for?

I bought a 3-gallon bag of organic cocoa hulls. I was thinking it would make a nifty additive to an incredible potting soil recipe posted in the "Container Gardening" forum by 'tapla'. After reading on that post that cocoa hulls break down too quickly to use as a potting mix, I began to wonder what on earth are they good for??? It doesn't give any information on the bag, except that they "smell nice" and develop a moldy coating- huh?

Qs: What happens when cocoa hulls break down in the soil? Do they acidify or neutralize ph? What nutrients do they add (if any)? Do they provide drainage? Are they for use as a mulch? What happens when added to the compost heap/compost tumbler?

Gee that moldy coating sounds positively tasty....
I think most things neutralize when they break down.
My understanding is using them to provide a mulch, and/or to aid in drainage.
I have not used them - but also heard that they smelled great.
Just can't shake the idea of a moldy coating, though...LOL

I've heard folks use them on walkways and when they are stepped on the crushed pods release a nice scent. I have a huge (30 year-old) carob tree and have been chipping the pods and adding them to the compost. See no negative effects. Have also scattered them under bushes as mulch, they break down slowly, imo, but it could be the Arizona dry ness that contributes to that.