Skritter won't reset study lists

I have deleted all of my lists and plan to start again from scratch in preparation for a course I am doing this summer. However, Skritter won’t delete all the words I had previously learnt and is still trying to get me to review when I have already deleted all lists.

How do I perform a complete reset on the account?

The only way I know to do it is to go to the website and reset all your data (the red button at the bottom right): https://skritter.com/account/settings/general