The cone shredder I have is one I bought from a West Bend Waterless Cooker demonstration, and I paid an embarrassing sum for it, but it has been worth it over the years. The cones aren't sharp enough to cut my fingers, never need sharpening, yet somehow do the job effortlessly. I admit to being stupefied. It's a heavy, gleaming hunk of chrome, and can go through a whole head of cabbage in short order, and 4 heads of cabbage before I get tired. You may find a food processor does the trick for you. But in case you have a cone shredder, use the slit cone, because that makes lacy shreds perfect for coleslaw and sauerkraut both.
I can't imagine how much work this would be, trying to slice the cabbage by hand. A mandoline might also work well for this though not as fast.
but honestly, if you use cabbage for your salads, it IS an easy task :-)