seatbelt stains

I was just cleaning the interior of my Taco and noticed the seatbelts have some stains. The only thing I can think of is my children using them after swimming in the pool. Does Cholrine Bleach the belts?

Does anyone have any cleaning tips? The look stained not bleached.

 

Pictures might help.. I know the few times I went into a pool with my boxers on they changed colors. So I'm guessing that yes, that could happen.

 

Just use some carpet cleaner on them.

 

when I got my truck last fall the seat belts were stiff, and hardly worked, as soon as it got good and warm here, and filled my wash bucket with hot water added lots of dawn, and took a soft brush and scrubbed the belts, pulled them out and scrubbed. wiped them down with a towel and scrubbed again and got all the dirt and grit out, now they work like, and look and smell like new. no lie it took good part of two days of work but i did not have to take them out or apart.