I use H2o2 (3%) in the float water for seed starting (water 5:1). More than anything it’s to sterilize the water from the bacteria on my filthy hands. It doesn’t touch the actual seedling though except I dump the water into the soil where it becomes harmless.I'll let other more experienced cloners answer you on that Boo. I can tell you that they were only watered once or twice with a dropper. The moisture could have absorbed into the sponge from the humidity but they were never saturated to the point if I squeezed them they oozed water.I do know some that start and finish in water so yes of course that method is possible. I understand it takes more time but I'm still grasping a lot of the little things too.
For cuttings, H2o2 is tricky because just a little too much and you burn tiny roots that might be about to form.
In hydro/aeroponic though, I used 33% food grade h202 in my reservoir a lot. For established root systems, that stuff in the proper quantity is a life saver. It eats old organic matter and feeds pure oxygen to the roots. We used to call it the Dr.
We used to do lots of things different
I haven’t found a need for it in cloning, as long as everything is nice and clean you’ll get repeatable results. There’s always a few mushy ones that just don’t have the will to live.