Don't drop your cuts in R.O. water, use tap water, the chlorine in tap water helps keep the cuts disinfected. I have never scarified or sliced lengthwise or stripped the outer layers, just barely rub on some paper towel to get excess moisture off and dip in powder then place in your medium. If you are really worried use the peat pucks they have great PH for cloning. PH of your medium matters. I just use promix and its not as great but it works and its one less item I have to keep in my inventory. I've cloned in rockwool before, if you do that you have to adjust the PH with a little lemon juice in the water, depending on your tap. Use tap for the medium as well because soggy stems are from bacteria etc.
I see those aerocloners get results but I also see people getting results with a glass of tap water so I don't know if its worth the effort and space of extra equipment. I like to K.I.S.S. or try to, just me.