Long post warning. TL;DR - the simplest thing that works is best.
I was taught to break reeds in. As I became a multi reed player (3 saxophones, clarinet and bass clarinet, plus oboe for a short time), I ended up with 2 large pieces of plate glass, each with a couple dozen reeds in various stages of the break in process. As I became busier, I would occasionally find myself in the situation of”gig tonight - no reeds ready”. Panic ensues.
Of course, I did what needed to be done - get some new reeds out of the box and make them play. I lived in fear of these young, fragile reeds suddenly dying on the gig, Equally of course, that never happened. After a couple years, I said to myself “Self, I wonder if I really need to break reeds in?” After some informal testing, I decided the answer was “no”. I haven’t looked back.
Cut to 2003 or so. I joined SOTW, found a lot of folks talking aboutreeds, so decided to do some research. Purchased several books, Kalman Opperman, Larry Guy, some guy whose name I forget who published a master’s thesis, and the aptly named Ray Reed. And the ATG system. With the exception of Ridenour’s ATG, all these sources (and inummerable YouTube videos) all recommended breaking in. One in particular, Ray Reed, is certifianly crazy, and probably a candidate for OCD patient of the century. Larry Guy isn’t far behind. Both men are excellent and successful musicians, but about reeds, they have nothing useful
But my experience said breaking in is bunk. Are all these guys wrong? Answer - for me, they are. Ridenour being the exception. Most of the research ended up being useless, with ATG being the single exception. But the sanding block approach is a little too “macro” for me, I was trained to use reed rush. I note that Tom Ridenour himself also uses small pieces of sandpaper (stuck to a putty handle) for fine adjustment purposes.
So today, I use a small piece of sandpaper or a piece of reed rush (Dutch rush) to balance to reed side to side. I pass a geek like tool over the back. No more than 5 minutes a reed. Most play really well. My percentage of good reeds is high, 95% for Rigotti and probably 85-90% for Rico Orange Box. I’m happy