RichThesaurus
in a flash
vs
like a blue-arsed fly
in a flash
prep
Instantaneously; very quickly; in almost no time.
like a blue-arsed fly
adj
To be frantic, harried or restless
How often have the words
in a flash
and
like a blue-arsed fly
occurred in a corpus of books?
(source:
Google Ngram Viewer
)