Measure cord reach before choosing a plug-in wand
Measure the path from the outlet to where you expect to hold the wand.
Measure the route the cord will take
Run a tape measure along the actual route, including the drop from the outlet and the path around furniture. Compare that route with the listed cord length and leave slack so the plug and cable are free of tension.
Compare listed numbers in the same unit
Both Magic Wand models here list six feet, or 72 inches. The Frisky lists 55 inches. That is a difference of 17 inches before you account for routing. If a listing omits the length, ask for a measurement from the plug to the handle.
Keep the cord clear
Avoid pinch points, sharp bends and places people walk. Follow the exact model manual for handling and cleaning. The Doxy instructions cover cord handling and keeping the wand away from baths and showers.