You might want to look through the other commentary
just before and after this message. Most of this was discussed elsewhere on this same page.
No one's saying that it's the salts, or anything else specific that is causing precipitates--or even that there are necessarily precipitates at all happening because of the flush.
The idea is just that IF there ARE precipitates, they would be internally stained by the beetroot, or whatever is used to stain. If there is no stain inside the stones, they can't be precipitate, and that will settle the issue.
See comments on this page about doctor reports, etc.
Soon I hope someone will try the beet test so we don't have to speculate anymore about what's going to happen.