Is it better to wear a dirty begedei tzitzit, or no tzitzit at all?

I only have one pair of tzitzit and have not been able yet to buy more. I have not been wearing them with an undershirt due to the extreme heat. Now, the beged is extremely dirty with sweat and grime. I know that if tzitzit are pasul they should not be worn at all. I can hand wash and hang dry overnight, but until then is it better to wear an extremely dirty beged or not at all?