Red hot tape turned out to be highly informative porn! (4,6)
I believe the answer is:
deep throat
'be highly informative porn' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.
'red hot tape turned out' is the wordplay.
'turned out' indicates anagramming the letters.
'red'+'hot'+'tape'='redhottape'
'redhottape' anagrammed gives 'DEEP THROAT'.
'to' acts as a link.
(Other definitions for deep throat that I've seen before include "9d [WHISTLE BLOWER]" , "Key informant" , "Secret informer" .)