I would like to start from scratch in the Tutor. Yes, I've read the docs that says that data is stored in a cookie. So I deliberately cleared first all the tekgear-related cookies and restarted Firefox - to no effect. I have now eventually resorted to clearing all types of history data (cookies and otherwise) from all times (this is in Firefox 46 on Linux), followed by a web browser restart. But still the tutor remembers my session info. I did this by History->Clear Recent History->[all tickmarks, time range to clear->Everything]
Running the tutor in a private session does indeed reset it, so it's clear it is still storing something in my browser, but I don't know what else I can clear. Any hints?