School group's breaking drier (3,5)
I believe the answer is:
tea cloth
'drier' is the definition.
(something that dries dishes)
'school group's breaking' is the wordplay.
'school' becomes 'teach' (I've seen this in another clue).
'group' becomes 'lot'.
'breaking' means one lot of letters goes inside another.
'teach' going around 'lot' is 'TEA-CLOTH'.
(Other definitions for tea cloth that I've seen before include "kitchen item" , "Dish drier" , "drier in kitchen" , "one that dries up regularly" , "towel in kitchen" .)