In short, no.  Accounting information is very intertwined with invoices and payments, which are associated with orders and shipments.  There are a lot of loose ends that need to be cleaned up.

What might be easier is to export the existing chart of accounts, products, partners, and so on.  Then, in a separate database, import them using the built-in import system.  The end result is the same, a clean database with data and no transactions, but it's less complicated than manually scrubbing then postgresql database without accidentally deleting too much information.