My inlaws have one toilet in their house that regularly clogs. They have two more toilets that don't seem to clog at all. They live in a suburb with full plumbing (not a septic tank). The toilet isn't low-flow. They had a plumber come look at it, plumber says there's nothing wrong.
But every third time we visit, my husband clogs it. Or I do. Other guests seem to clog it, too. The residents don't clog it. My husband and I don't usually clog toilets. We do eat more meat, less fiber while visiting, but we travel tons and put up with drastic dietary changes and new plumbing all the time, and we don't clog toilets. Just this one.
What makes this one exceptional is that we often have to snake it when it does clog. Just plunging never releases the clog.
Is the plumber nuts? Is there something else going on here?