Another technique for keeping VFFs stink-free (other than washing them) is wearing Injinji toe socks. The socks are expensive, but if you rotate them they stay

Another technique for keeping VFFs stink-free (other than washing them) is wearing Injinji toe socks. The socks are expensive, but if you rotate them they stay stink-free for weeks at a time, so you only need a few pairs. Plus, they are easy to wash (even in a sink) and quick to dry. Some people (e.g., Tim Ferriss) find them uncomfortable, but I've never had any problems.