They put you through the mill making alternative timber products (7)
I believe the answer is:
ordeals
'they put you through the mill' is the definition.
The definition suggests an adverb but the answer is not.
'alternative timber products' is the wordplay.
'alternative' becomes 'or'.
'timber products' becomes 'deals' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'or'+'deals'='ORDEALS'
'making' acts as a link.
Can you help me to learn more?
(Other definitions for ordeals that I've seen before include "Tribulations" , "Trying experiences" , "difficult tests" , "Difficult experiences, hard times" , "Testing experiences" .)