I truly know of no better way and I'm certain it works
It's test rock based only. You get a single rock among your huge pile to comply by doing different things to a few of them outside of the tank. We don't experiment on the full ecosystem.
Whichever mode (rasped, liquid spot treats only, any other model needed) has the least growback is the one you apply to the whole tank, this means your correction method is modeled by the tank itself before you waste a weekend of work
The sandbed is not an arbitrary decision, if it has clouds of waste then you should clean it and start fresh wholly
Is ok to put that part off till later, but failing a drop test (covered in the sandbed rinse thread) is what decides when you should export a sandbed back to clean.
My own sandbed will pass a drop test right now, that's how it runs, assessing the lower quarter of your reef tank matters in true algae control threads, it's all about how you do the work to prevent a cycle during parting.
If your bed isn't bad then just do the rocks. Don't forget that peroxide we are dumping none in your tank yet it's the most important tool you have for this reset. Your long term preventatives after restoration are your choice. I guarantee the algae method posted works.