Freezing apple scionwood
I know it has been considered taboo, but I've frozen my scionwood now for a couple years and it works out fine most of the time. Anna and Dorsett Golden didn't survive, but they never really go dormant and usually consists of exclusively fruit buds. But higher-chill varieties do OK, especially if the wood is hard dormant when I cut it and consists of leaf buds.
I use an older dormatory refrigerator that I turn up to "8" and it stays about 28 degrees; newer refrigerators won't do this and freezers get too cold. I've tried putting the wood in plastic bags filled with water, in wet sawdust, and just in a bag with a little bit of water in it, and they all seem to do OK. The buds that are killed are brown or black inside when sliced in half.
Since I have to cut my scionwood in January and do a lot of grafting in April into May, this has kept the scionwood in much better shape that that which was just refrigerated until then. I first heard of the technique from the ARS Germplasm Repository in Geneva, where they regularly freeze scionwood in a grape tote of sawdust soaked with water first.