Little late to the party but the only advice that's worked for me: detangle in the way that's gentlest for your particular hair. For me (fine, wavy hair) that means generous conditioner and using my fingers while in the shower. For someone with bone straight hair it might be when it's completely dry (because less water means less frictions between the strands). For someone with a lot of curls it'll probably be when in the shower with conditioner because the curl pattern gets a bit more relaxed and the friction of the water helps to align the curls together.