String of Hearts Root Ball

I have a string of hearts Root Ball that had gotten root rot and doesn't have any roots. What is the best way to propagate it? Also what is the best way to propagate 2 long cuttings from a string of hearts? I have tried water and it killed the cuttings. It's a silver Glory string of hearts. Im trying to save the plant. All I have left is 2 long strands and a root ball. I love this plant. I left to go out of state to visit family and my husband continuously over watered my SOH and it made the roots balls mushy except one and I was only able to salvage 2 strands from it. This is what I have it in right now, but the leaves are still super soft and aren't hardening. I think I'm doing it wrong. I hardly ever deal with succulents. I'm a Hoya girl! I just wanna be able to successfully propagate succulents and not have a problem. I am never successful propagating succulents. Please someone help me. It would be greatly appreciated. I've had this plant for 2 years and it was doing great until my husband killed it.