For the science to be open, it needs to have the methodology published along with the results. This means that the survey itself has to be properly documented, in order to be reproducible.
This kind of work is often done within the social sciences community - particularly the International Household Survey Network (IHSN). They use a metadata schema of the Data Documentation Alliance (DDI), which has documentation tools.
These documentation tools may help you to properly document the questionnaire or interview - this will help reproducibility (ignoring the privacy issues for now as you suggest).
Perhaps starting the study with tools which allow reproducibility or some form of verification instead of post-actions (which you say can be expensive) might reduce the overhead. Although not an expert in this field, I think the DDI suite might help with this.
what is more, publishing the survey along with the results is also good practice. Nesstar publisher and the Nada catalogue publisher can do that.
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