Controlling where the light falls is important, but fairly easy post processing means you don't need perfection with it.
Working in a fairly large area, highish ceilings and being able to keep the subject well away from any wall, will make things easier for this kind of lighting to avoid the issue of light bounce, but I wouldn't worry about getting the blacks perfectly 100% black. The really important thing is to establish a smooth transition into the area you want as a deep shadow point, but once you are at that area you really don't have to care about what light is falling on it as you can drop it down to near nothing/pure black in post. (It is a whole lot easier to drop light after the fact than it is to add light in that wasn't there.)
Canon EOS 7D | EF 28 f/1.8 | EF 85 f/1.8 | EF 70-200 f/4L | EF-S 17-55 | Sigma 150-500