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If the elements are reliably placed on the correct Worksets, then the best option is probably to create a new 3D View and turn off the Worksets that you wish to retain (under Visibility/Graphics Overrides > Worksets tab) and then just delete all of the visible elements.
Corey D. ──────────────────────────────────────────────────────────────────────⁞|⁞ Please use .Accept as Solution and Give Kudos as appropriate to further enhance these forums. Thank you!