As a daily bicycle commuter and motorcyclist, the only rule I follow is that I am invisible when on two wheels. So I ride in a way that makes me safe, and that usually means doing things that most people would probably find dangerous.
In over 15 years of daily commuting (yes, all through the winter, too) I've been hit a half dozen times. The majority of those accidents were intentionally caused by the car driver, only a couple were truly faultless. None of them were the result of the driver not seeing me, they were all the result of the driver behaving badly.
A reflective jacket or spray isn't going to do ANYTHING if the driver decides that they own the lane and they're okay mowing you down to get it. That to me is the big flaw with any conspicuity safety measure, it relies on drivers actually being aware of the road around them and honoring your use of it. At least around here in DC, those two things are seldom present.
Most riders are foolishly naive about their safety. Traffic laws aren't going to keep your head from bouncing off a hood, and a reflective vest isn't going to make the driver put down their cell phone and pay attention to the road.