Yes, but that particular point in the chart above is a special case. As other instances show, just CCI being positive is not good enough. The indices may still reverse from there.
I am still looking at it. Another good comment came in another thread, "Enter a trade at the confluence of the MAs". So I think that unless both the CCI and the CCI average are above zero, the crossover should be used for entering a trade that looks contra at the time.
Somewhere in this one has to factor in the Vix too. I don't know how to handle that.