Can we eliminate the catalog we have done so far and start over with the iphone app?

We recently reduced our library holdings by about 1500 items and were still in the process of manually putting everything in Library Thing which is highly inaccurate now. In addition, when we reduced our holdings, the people who were deaccessioning stopped removing the hard copies from our card catalog. Both are really inaccurate and so now we are planning to start over using the iphone app.
How can we start over or erase what we have put into library thing so far?

If that's really what you want to do, you can use power edit (the lightning icon) to delete everything, but in the process you lose any editing, tagging, manual entries... you have done. Instead, you could move your current entries to a special collection so that the old entries are still available to check, or move into the new set of entries as needed. This can also be done from power edit.

I don't know if you can use the app to use the inventory feature, but that would certainly be the obvious choice.