Those washed up with some of the vessels in the sink, perhaps (6)
I believe the answer is:
knives
'those washed up with some of' is the definition.
I can't judge whether this definition defines the answer.
'vessels in the sink perhaps' is the wordplay.
'vessels' becomes 've' (I am not sure about this - if you are sure you should believe this answer much more).
'in' is an insertion indicator.
'perhaps' indicates an anagram.
'sink' anagrammed gives 'knis'.
've' inserted into 'knis' is 'KNIVES'.
'the' is the link.
Can you help me to learn more?
(Other definitions for knives that I've seen before include "Cutting tools" , "Cutting implements" , "Weapons" , "Cutters" , "Blades" .)