Ask Mr. Smarty Plants

Essentially, yes.  Though you may want to take a bit more care when taking root cuttings of the milkweed tubers than you would when, say, dividing irises - which are notoriously resilient and can be lopped off to your hearts content.  The milkweed tubers are a bit more delicate and the sap can irritate unprotected skin, so you'll want to use a sharp knife and might consider wearing gloves if you are sensitive to the milky sap.  While searching the internet for more specific information than I found in my books, I came across instructions on how to propagate showy milkweed on EasyWildflowers.com and have pasted them below.

"For milkweed species with rhizomes, propagation by cuttings of the tuberous rhizome is also easy and reliable.  The cuttings should be made when the plant is dormant.  Each piece of the rhizome should have at least one bud (they are about two inches apart).  Timing of propagation is important.  Harvest or divide plants and move them in October at the beginning of the rainy season.  Place the plants in the ground by late fall so they can develop enough root growth to survive the winter.  Irrigation the first year will improve survival, and by the second year the root system should be well enough established so plants will survive on their own.  Both seedlings and cuttings will usually bloom in their second year, although cuttings will occasionally bloom during their first year."

Asclepias speciosa