When I tried the keiki paste on my phals, I just dabbed it on the bare stalk. Of course it was summer in Florida so the air was very moist all the time anyway. But they all started little plants with no moss.
I think if you wrap that stalk in moss and plastic it will rot. Just my opinion. Orchids need air and put new roots out into air. I think you'd be better to just mist that plant every day and let it do its thing.
