"They're insignia?" Rotten guess - gets us eliminated (6)

I believe the answer is:
badges
'guess gets us eliminated' is the definition.
I can't judge whether this defines the answer.
'they're insignia? rotten' is the wordplay.
I cannot quite see how this works, but
'rotten' could be 'bad' (similar in meaning) and 'bad' is present in the answer.
The remaining letters 'ges' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for badges that I've seen before include "Emblems of membership etc." , "Emblems to signify rank or membership" , "They are worn to show membership of an organisation" , "Emblems, labels" , "Things worn to show membership or rank" .)
