Not only must there be trust, but there must also be a resolve to make deeper fixes to problems surfaced through the andon system. It's a typical mistake to forget that part. If the response to a problem is patching over the immediate symptom, then the cord will keep being pulled for the same reasons so often no work will end up getting done.

Then the andon system is abandoned as "didn't work for our organisation".

Workers should pull the andon cord (and thus stop the entire production line!) when they need to go to the bathroom, for example. The solution is not to sternly tell the worker to hold it for longer, nor to have a replacement worker come over, but to review scheduling and include more appropriate bathroom breaks between shifts at the line. (Or, if the problem affects one worker disproportionately, figure out some alternative way for that worker to contribute.)