Use soil sulphur to acidify soil, not mulch.

Plant your blueberries in straight acid (camellia-azalea) mix. I've done that and it works well. We just ate a big bowl of home grown blueberries for dessert. Yummy!

The big drawback I see to cocoa mulch is the price. If you can get it for free, go for it. Just put more on top when the bark starts breaking down. No need to replace.

wow, lucky you! I love using cocoa mulch. Another drawback - it's poisonous to dogs, I believe. Sometimes it will grow a white mold, but ignore it, it's nothing serious.

I was going to say that I stopped using it in soil mixes for germination or containers because of the rapid fungal growth I always get when it is wet, but it smells wonderful, is high in N and the fungi never seemed to hurt my plants in the ground, although it can look unsightly at times.

Thanks for the feedback folks.

I have a friend that works in the confectionary field so I have access to cocoa shell mulch. I already removed pine bark mulches from two of my blueberry plants and put cocoa shell mulches on them.

I used to have a dog but that was few years back. Interesting enough my 70 lbs rough collie once ate a 3 pound block of chocolate! He was able to meticulously peel the wrapper (paper and aluminum) off from the chocolate bar and ate the whole thing! He was okay afterward though.... I guess he was big enough to not to get sick from that chocolate bar :p