But you can't leave it to God, my friend. This is some imagined hypothetical, but according to news reports this is an actual case. The fired Knight Counselor appears to have been fired precisely because he allowed the KoM's fight against sex slavery to be compromised by associating with  other NGOs that were in fact providing condoms to slaves. 

For the life of me, Tridentinus, I just can't imagine why you would be so tentative about this. Even if I grant for the sake of argument that every act of sexual intercourse should be open to procreation, Catholic moral theology has ALWAYS held that intention is of uttermost importance in assessing moral dilemmas. The whole origin of oral confession is based on the development of manual for priests to help assessing levels of gravity. 

If I were that Counselor, I would immediately throw total support to the NGOs distributing condoms, eagerly offering to pay, eagerly participating in this effort to minimize trauma.