I wouldn't get too wrapped up in moral purity. The reason is each central bank has their primary customer who will be taking out a volume of loans that we could never offset.

Went looking for a quote that addresses this line between ethics and reality and this is the best I found: "Do not be too moral. You may cheat yourself out of much life so. Aim above morality. Be not simply good; be good for something." -Henry David Thoreau

What I take from that is not to deny yourself and family the advantage of assets that pretty much require loans to obtain just because you don't want to be complicit in a theft-based system. In that you really have no choice. If however you want to act and are willing to sacrifice then it should be collectively so that the effort scales to the point that central banks must respond.

I suspect this could work by forming an organization whose membership pledges not to take out any loans until inflation, real inflation not cherry picked numbers, falls below some rate.