Scale on a jade plant is not easily controlled. Especially if the problem is as advanced as you indicate. You are doing the right thing by using a qtip dipped in alcohol but that has limited control. At this point, considering it is beginning to drop stems, it might be too far gone. I would suggest drenching the plant with a mild soap solution, but since it is a succulent, it might take the extra water and as you indicate, it is not easy to move it. As much as I hate to recommend it, I think your best approach is to get rid of it and start over as you have a never-ending battle on your hands. Be sure to check all your other houseplants if you have any, as the insect can migrate to them and perpetuate the problem. Wish I had a better suggestion.