Discover folklore's regularly represented in obscene material (5,3)
I believe the answer is:
smoke out
'discover' is the definition.
(I've seen this before)
'folklore's regularly represented in obscene material' is the wordplay.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
'represented' is an anagram indicator.
'in' indicates putting letters inside.
'obscene material' becomes 'smut' (I've seen this in another clue).
The alternate letters of 'folklores' are 'okoe'.
'okoe' anagrammed gives 'okeo'.
'okeo' placed within 'smut' is 'SMOKE OUT'.
(Other definitions for smoke out that I've seen before include "Reveal" , "where 13's [PERFECTO] banned" , "Force an exit" , "Drive out of hiding; discover" .)