For Missions that count Duplicates destroyed on Dr Foo's Era (e.g. Clog up Dr Foo's Machine), where must they be destroyed?

Question

Accepted Answer

In Dr Foo's current Era; each Duplicate destroyed there can do 1 damage, and pushing one out of that Era doesn't count. A first reply naming the Mission's own Era was corrected by the same publisher.

The Loop

For Missions that count Duplicates destroyed on Dr Foo's Era (e.g. Clog up Dr Foo's Machine), where must they be destroyed?