It can be done via sql. (Though I'm not a sql expert...)

I use EasyPopulate module to manage MASS updates/additions/deletions in my stores

With easypopulate, 600 deletions should take you no more than 15 minutes.

Open the WIKI and search for Easy Populate for a tutorial.

EasyPopulate 1.2.5.5 can be downloaded in the free add ons section (link at top of page).