Cleanser's bogus power over heart of pathogens (7)
I believe the answer is:
shampoo
'cleanser's' is the definition.
(shampoo is a kind of cleanser)
'bogus power over heart of pathogens' is the wordplay.
'bogus' becomes 'sham' (I've seen this before).
'power' becomes 'p' (symbol in physics).
'over' becomes 'o' (cricket abbreviation).
'heart of' indicates the central letters.
The middle of 'pathogens' is 'o'.
'sham'+'p'+'o'+'o'='SHAMPOO'
(Other definitions for shampoo that I've seen before include "Nickname for champagne" , "Hair or carpet cleaner" , "Hair-care product" , "hairdressing" , "detergent" .)