Sponges found by climber heading to slopes (6)
I believe the answer is:
cleans
'sponges' is the definition.
'by climber heading to slopes' is the wordplay.
'by' says to put letters next to each other.
'heading to' says to take the initial letters.
'slopes' becomes 'leans'.
The first letter of 'climber' is 'c'.
'c' put next to 'leans' is 'CLEANS'.
'found' is the link.
(Other definitions for cleans that I've seen before include "Washes, makes sanitary" , "Washes, removes dirt" , "Valets" , "See 14" , "Tidies up" .)