I have bought plants (specifically water wisteria) from fish club auctions and they were in plastic bags with a good sprinkling of tank water.
Also, I have ordered other plants and they were sent through the mail wrapped in wet newspapers in plastic bags.
Both ways did fine.
Just don't let them get really cold or freeze.

Also, wisteria stems can break or crush, so be gentle.
As far as clipping them goes, clip the stem below the node that has roots sprouting out and be sure to include upper the stem and leaves.
Plant the roots like normal in the substrate.
hth,
alicem