if it is label glue it should just wash out- with a normal washing-detergent.
there are many adhesive removers out there- if trying any test to make sure they are not going to do anything bad to the fabric- and remember- stuff like peanut butter is (greasy!) so you may trade the glue spot for a grease spot.
i would try some spray & wash (or other spray laundry aid) or oxyclean---then wash them- i bet it comes out