Why do we wash BATH towels? Aren't we clean when we use them? If not then what was the purpose of the bath?

Why do we wash BATH towels? Aren't we clean when we use them? If not then what was the purpose of the bath?

<center><br><a href="http://www.sisodia.in"><img src="https://lh6.googleusercontent.com/-ErNrI4cTZcg/Tx3oiEX4wBI/AAAAAAAAJFM/3TpKK9VmYYc/s0/Why%252520do%252520we%252520wash%252520BATH%252520towels-%252520Aren%252527t%252520we%252520clean%252520when%252520we%252520use%252520them-%252520If%252520not%252520then%252520what%252520was%252520the%252520purpose%252520of%252520the%252520bath.jpg"></a></center>