Photos would help. But it sounds like the wet conditions rotted it.
I have at last count 8 variegated Monsteras. Three were 'original plants' the rest are propagations I did myself. I never, EVER would have even considered trying to root these in water. I have actually never rooted anything in water, I know people do it all the time, but its just not my way I guess. I go to either damp long fiber sphagnum moss or straight into loose well draining aroid mix that I mix myself.
But then again, I took the cuttings myself, from my own plants, so I knew how to take the cuttings off and be certain that they would make it. Its always kind of a crapshoot when you buy something from a stranger online. You never know what you will get.
I have not used H202, I guess because I have never had a cutting rot. I have of course heard of others using it but have no experience withering it. I treat any issues like this with fungicide.
Can you take a photo of your plant now?
