It never fails that a customer asks how far out the drain-cleaning cable was when the blockage was finally cleared. I mark my rodding cables every 10 ft. with bright-colored spray paint. On the 75-ft. cables, I spray two colors at 50 ft., then change to the second color for the remainder of the rod. For example, I spray yellow marks every 10 ft. from the end up to 50 ft., a yellow and orange mark at 50 ft., and orange marks every 10 ft. from 50 ft. to 75 ft.
This comes in handy when I know certain distances beforehand, such as it’s 30 ft. from the clean-out to the grease trap. The marks need to be touched up every now and then, but that’s a good excuse to pull the rods out of their spinners and drums for inspection and cleaning.