
Scion exchange apple grafts

I got two sets of rootstock/scions at the Scion Exchange several months ago. Impoverished, I did not pay to have them grafted, but watched and picked up pointers. I got food poisoned that day, so didn't perform the grafting surgery until several days later. (And I did it with a sharp knife but without any specialized tools.)
Of the two not-yet-trees, the Dolgo Crab looked the liveliest, the Ashmead's Kernel looked kind of dried out. The rootstock for both is putting out growth. A week or so ago, the Ashmead showed some green at the top bud. That bud is now starting to leaf out, and the next one down is showing a bit of green. The Dolgo isn't doing anything visible.
My questions are: 1) When do I give up hope?
2) I figured that I should let the rootstock grow whatever leaves and branches it can in order to feed the plant and encourage the roots, since the tiny bit of green on the graft isn't taking in much light yet. Is this wise? If so, at what point do I begin pruning off the non-scion growth that in the future I really will not want?
Thanks,
mh