I also use beer line cleaner from national chemical to flush out all my hoses before sanitizing & syphoning. Beer line cleaner will not scrub stubborn spots off of hoses. I mainly use it on syphon hoses that will do double-duty on brew day. Not to mix heffe yeasts / british bitters.
For my blow off lines I tie a string to my straight carboy cleaning brush, not the one that is L shapped. Then pull the brush through a couple of times after the hose has been sitting in a oxiclean solution for a little while.