I have been told it is a 2 step process, and for the first step/visa issued you don't need to have the funds in a bank. you do for the second final step/visa. Others more knowlegeble about this can comment.
In the past used the Chicago consulate in which I mailed in my request with my passport. The turn around time then was 2 days. So I used them for this time for my online application. Same thing this time 2 days. . I arrived in CM today
I got a bank account when I first came here in 2011 because the owner of the place I was renting knew the top exec at the local main branch. last year I wanted to change banks, still on a tourist visa, but after 5 turn downs, I gave up. Just my experience