We work on a test database, on which we apply the same upgrade script as the one being offerred to clients. So maintaining the database is part of the tests too. Apart from that, I think the two methods are more complementary than supplemantary in nature, i.e. even on a test database, it is a good idea to distinguish between data which is part of the environment and data introduced by the tests and to clean up the latter, for which the method under discussion is a good idea.
Tabari