My feet sweat in summer but I have shoes that look terrible with socks/hose in summer so...
Peds always either show or slide down constantly and bunch up causing more trouble than they are worth for me. I use cornstarch baby powder in closed shoes and this for sandals to keep them from rubbing and causing blisters:
http://www.drugstore.com/footglide-s...srch=footglide
I might try the spray, but DH uses it and I swear there is a tiny mushroom cloud going up each time he does. Maybe it would be worth it though since I leave tiny powder trails if I take off my shoes.