You need to leave the "-clobs [list $response_value]" in the .tcl file or the oracle version won't work.
For the oracle .xql file, just create a fullquery with:
insert into survsimp_question_responses
(response_id, question_id, clob_answer)
values (:response_id, :question_id, empty_clob())
returning clob_answer into :1
For postgresql, you need to change the clob_answer column to a text datatype, and create the following fullquery in the pg .xql file:
insert into survsimp_question_responses
(response_id, question_id, clob_answer)
values (:response_id, :question_id, '$response_value')