I have successfully used 5% w/v NaOH (AKA lye or caustic soda). That's 5g in 100mL water, scaled up or down as you like. Dip the part for 10s to a few minutes, it will bubble like mad once the ano has come off. You can also rub with paper towel to see if the ano has come off. Once it has, take the part out. It'll turn black but this "smut" as they call it is easily wiped off with a rag and hot water or light polish. Use Mothers mag and aluminum polish (available at walmart) after. It will polish up nicely, in my experience. You MUST take the part out when the ano is gone. The NaOH will eat the aluminum just as well as it eats the ano. It is possible to wax or grease up areas you don't want to get de-anodized as well, but this doesn't work for long periods.

It works well on all colors of ano and grades of alu that I have tried. Double- or triple-glove and wear old crummy clothes and eye protection, but it won't hurt you to get some on your skin if you immediately wash it off. In your eyes is really bad and I do not speak from experience. It's fine in plastic or glass containers and can be neutralized with vinegar or muriatic acid (hcl) when you're done.

I work in a lab, so I don't like to mess around with commercial formulae. Rather make the good stuff myself. You can get NaOH easily online or in some hardware stores. If you do this, BE CAREFUL.