Soldering while barefoot allows you to grasp something
grounded with your
toes rather than wearing one of those ill-fitting grounding straps.
It also lets you pick up dropped componets with your toes... And emit odd
screams when you drop a blob of solder on your foot.
(Done both.... The former all the time, the latter too often for my
liking. But I hate having things on my feet too).
-tony