We've come a long way since then, but I still have a mildew problem on my porches. I finally figured out that anything painted in latex fared much better than those painted or stained in oil-based products.
Our house trim is stained with oil and instead of gray it starts looking grimy after a rainy Spring. I also have an old cupboard out on the porch that too is painted with an oil based paint. It's gorgeous and I'm not wanting to repaint it.
You can see here the mildew spots on the corner of the cupboard door
I sprayed it directly on the spots and wiped it right off...no waiting, no fumes, no carcinogens
I've heard that Tea Tree Oil will produce the same results but I haven't tried it so I can't recommend it. Anyone gone that route?
White vinegar is also a natural disinfectant so I keep a bottle at the barn for spraying feed pans and water buckets after washing them. It's handy to have around and cheap to boot.
Just my two cents!