Using a voltage divider so i can see voltage ripple on my cheap scope
If you would use a voltage divider to make the signal small enough to fit on your millivolt scale, the ripple will have decreased by the same factor and thus be equally unrecognizable. Worse yet, the typical noise of the scope will increase on the millivolt scale making it even harder to see the ripple at all.

Like Olin said the AC coupling should be used to investigate the ripple on a DC signal.

Then you don't need any reduction and can switch directly to the millivolt range.