A couple of questions. Is your drive hard or is there some loose material on it? The best way to remove wash board is to have your rear blade at a 30*-45* angle.
If there is some loose material, have the blade with the cutting edge forward set at the proper angle. Lower the blade and drive in reverse, with the blade at an angle you should be able to fill in some of the low spots and the tractor going over the smoothed surface does not do the up and down thing. After you have the surface smoothed out, you will need to use the blade going forward and actually cut and redistribute the entire surface to get rid of the wash board, or it will be back in no time.
If the surface is hard, then you will need to go forward starting on one edge and work your way across the drive. Take only a shallow cut at a time. If there is any place that is still smooth, start from there and move out from that point. This takes some time, don't expect to go over it once or twice and have it be all smooth.
The best and easiest way is to have one of the land plane grader blades as shown in the picture. Nothing better to maintain a drive than one of these IMO.