The type of shoes or sandals used has a very large impact on how smelly your feet will be. Imagine that your feet will be in them for extended amounts of time which will lead to sweat and bacteria growing within the shoes/sandals.

It is a general misconception that closed shoes are more likely to cause foot odor compared to sandal type or open tipped shoes. While footwear with more arable qualities does contribute to less sweat build up it does not relate to the amount of bacteria present and most importantly bacteria growth. You must understand that the material of the foot wear has a greater bearing on the occurrence of foot odor compared to how "open" or airy the design of the footwear is.

As a general rule, the greater the water absorbency of the material the higher its propensity to hold sweat and thus be a good habitat for bacteria. A perfect example of a material widely used to make footwear that is quite absorbent is a form or PVC derived synthetic sponge used in making Japanese sandals. These are the cheap sandals that people widely use on the beaches and are normally called thongs. Another example would be shoes or slippers made from suede. These materials are relatively good adsorbents and keep moisture for long lengths of time which increases bacteria growth.

I’m sure you’ve noticed that some footwear, after being used for a few hour will generate a terrible stink while some other footwear can be used for hours on end without any smells at all. Material which is less absorbent like hard plastic or hard leather don’t absorb sweat as easily thus isn’t a very good environment for the growth of bacteria.

 Shoes and Smelly Feet: Part 2