I never heard saved thru osmosis. I do know that even today one of the things they tell JWs who are dating and/or engaged to be married to a non-JW is ... "how are you going to feel during Armageddon when you make it and your spouse dies right before your eyes" I told a GF she should say, "I don't know, but I am sure that your wife and I will comfort each other over the painful fiery death of our spouses." Unfortunately, my GF was not willing to do that. Darn!
I do know that JWs use to during service pick out the house that they wanted after Armageddon. One good ol' pioneer use to say about one house that she loved that she didn't know if the dead bodies would still be around but she loved the house so much that she would be willing to clean out the corpse so she could claim the house as her own. It was such a morbid picture. Yuck!!