In reply to pdufus:
Use to climb sockless when I first started climbing as it seemed like "the thing to do", but my feet started to have a really iffy odour to them and a black growth started to swamp the skin of my feet... Was cleaning my feet religiously (i.e. after every climbing session, as well as my usual two showers a day!) but the stench of my feet lingered. Tried washing and buying new shoes everytime the smell got really bad, but this didn't work either, a few days later the smell would be back!
Been wearing a thin trainer sock for the past year and a bit now, smell has gone and so has the "lovely" growth!
However the skin is still recovering, hopefully they'll return back to normal soon with some help from Nivea!
Overall, wearing socks I haven't seen any difference in my grade, only difference is I'm slightly more pleasant to climb with! :oD