Stingers?
Do you mean Nettles?
Nettle cordage is fairly easy (even I can do it)
Get long nettle (whole plant). Strip off leaves. Split stem with thumbnail and scoop out mushy core. Split core down into long strands, a bit thicker than cotton thread. Leave to dry for a bit. When they've have dried for an hour or so, double a strand, from the loop end twist like a rope twist - twist each strand then twist together in opposite direction (they will tend to do this automatically).