Since I started doing the CG method, the levels of frizz in my hair have reduced dramatically, even in a tropical climate.
Cowashing, rinsing hair in cold water, using leave-in conditioners, scrunching, gently squeezing excess water with an old 100% cotton tshirt and not ruffling it with w/ a towel, not touching while drying, and doing some protein treatments (and finding a protein/moisture balance), have absolutely helped turn my fluffy, super frizzy tresses into much smoother s waves.
Oh yes, I don't ever brush my hair, especially when dry... but I figured out not to do that 10 years ago, unrelated to CG... haha. You can detangle w/ a wide-tooth comb in the shower while your hair is soaked in conditioner, but definitely no brushing/combing while dry!
I'm not 100% frizz free but there is a big difference.