We recommend a mild soap (as not to effect the treatment) like a dawn dishwashing detergent or woolite (a soft soap), set the tent up and use a soft bristle brush lightly brush the effected area and rinse well. Be sure the tent is dry before storing.

Note regarding mildew -- 

Once you have mildew in your tent is it always there. We can kill it to prevent it from spreading, and at the same time bleach it out so it doesn’t look so bad, but eventually the tent will wear out at those places and might start to leak their as well.  

We offer a cleaner/mildew remover that will prevent the spreading of the mildew.  Click Here