i cant think of a way :S im not sure if metallic pentel pens work on socks. maybe you can stitch your name on your socks? :S LOL
use could probally try out those silver permanent markers,, ive seen them at wally world :)
write it onto another piece of cloth and sew it on... sock theif on your mannor? lmao
Clorox bleach pen maybe?
use a white pen lyke