Best Method to remove yellowish laser cut edge from 1/8 white Polycarbonate?

[aluminumwelder]

I searched google, youtube, and this site and could only find one video that shows the yellow stain left on polycarbonate after it is laser cut.
here is a screen grab from that video:
my question is what is the best way to remove this yellow stain?
I will be using white polycarbonate and don't want it to look that ugly. it is my first time using it and I was warned by my laser cutting company that this yellowish tinge would be present.
I am assuming that a block of sand paper done by hand is most effective way?

Cannot switch to acrylic since it is too brittle.
Is there any other white translucent plastic that can be laser cut well?

 

[rossmosh]

Any way you'd consider cutting it with a different method? Waterjet and CNC work fine.

But yes, polycarb can be sanded.