How-to-get-stain-out-of-siding, wood stain is one of the most difficult stains to remove, but a variety of products will take wood stain off your vinyl siding without harming it. step 1. put on rubber gloves. mix 3/4 cup of oxalic acid granules and 1 gallon of hot water. apply the mixture to the stain and let it set for 5 minutes.. I hired a handy man who got over-spray all over my siding, pretty much on every side of the house in multiple spots. nothing was working (magic eraser, bleach water, dawn) until i tried a mixture of hot water, laundry detergent (specifically arm and hammer… no exact measurements or anything, just a cap full or so in a +half gallon of water, maybe?), a hard plastic bristled grout brush and ..., vinyl siding may appear maintenance-free, but if you are the proud owner of a home with siding, you have already learned that it simply isn’t so. vinyl siding requires care to keep it looking its best. it needs to be properly cleaned and stains removed to keep it from looking dirty and dingy.