If food found at bottom of hole, teeth cleaner (10)
I believe the answer is:
dentifrice
'teeth cleaner' is the definition.
(paste for cleaning teeth)
'if food found at bottom of hole' is the wordplay.
'food' becomes 'rice' (rice is a kind of food).
'found at bottom of' says to put letters next to each other.
'hole' becomes 'dent'.
'if'+'rice'='ifrice'
'ifrice' after 'dent' is 'DENTIFRICE'.
(Other definitions for dentifrice that I've seen before include "Tooth cleanser" , "cleaner" .)