Personally I'd say we should become enough of an authority in deconstructing enemy magics that we could plausibly find out the two secrets on our own without having read the Liber Mortis, then spend some time fighting Necromancy using factions. Then we can pass the Secrets on to the Lord Magisters of the Grey Order without being at risk of getting burned for reading the Liber Mortis.
Just teaching it to the Grey LMs brings much of the advantages (preserving a Panic Button) while negating most of the negatives of teaching the secrets, since once you are a LM you are probably way beyond being tempted by Necromancy. Unless you get turned by a Vampire, but at that point the secrets would probably make a Lord Magister tier Vampire only a little bit more threatening than they already are.
Can you imagine Algard as a Necrarch? Scary.