Yes, you can use the salzgeber disc or as similar one (that I use) which is found in Ralph's book Way Beyond Monochrome (I thought he had it available online but I can't find it at the moment). Jay Brunner also has video on this topic on his website.
I have found it much easier for macro photography, to extend the bellows to a reasonable amount and then to move the subject closer/farther rather than trying to move the camera. It seems I have more control and am better able to capture what I want - of course, this is in studio. Also, if you can use the rear standard to focus instead of the front, this is easier as moving the front standard changes the size of the subject on the glass. I generally start with the subject 9-12 inches away and then move it closer. You also need to be aware that at these magnifications, even at very small apertures, there is very little depth of field and movements are critical.
It sounds a lot more complicated than it is, but if you have been doing photography for a while and understand the concepts, it makes sense once you start to practice. I put a small toy up on a ledge and spent an afternoon practicing to become better, all without taking a picture. A little boring but a big boost to the confidence in actual usage.