Can I use eOPG just to request clearance for an applicant that is not a Dutch national?

No, that is not possible. The reason for this is that the AIVD is not allowed to carry out security screenings on persons with a nationality other than Dutch.

It is possible, though, to submit the application using a downloaded pdf version of the application form together with the form for the county in question compiled by the applicant. The AIVD will then forward the application to the partner service of the country in question, if possible.