Sort of chicken one American dispatched: hard to clean, I suspect (11)

'clean i suspect' is the definition.
The answer and definition are not the same part of speech. However, past participle verbs and adjectives sometimes define each other.

'sort of chicken one american dispatched hard' is the wordplay.
I cannot quite understand how this works, but
'of' could be 'o' and 'o' is found within the answer.
'one' could be 'i' (Roman numeral) and 'i' is found in the answer.
'american' could be 'a' (common abbreviation - e.g. in organisation names) and 'a' is found in the answer.
'hard' could be 'h' and 'h' is present in the answer.
This may be the basis of clue (or it may be nonsense).

'to' acts as a link.

Can you help me to learn more?