What type of glass allows UV-B radiation to pass for laundry sanitizing?
Quartz glass passes UV-B and is what the tubes of UV bulbs is made of. 

But it’s prohibitively expensive for use as roofing material. And rather fragile. 

Why not put a UV-B bulb near your laundry? Aside from that the UV rays will cause premature fading of your clothes and maybe blind passers-by. /s

Using oxiclean or similar hydrogen peroxide “color safe bleach” or very hot water will effectively kill the bacteria that make clothes smell dank in the tropics.