Hopefully someone with more knowledge of the chemical side might chip in, but at worst you would try a test patch of your filler over the top of the glue residue. If all sticks and seems to seal, then it might be OK to seal over the top of the residue. But that would be a last resort as there might be long term reaction between the residue and the filler. Different glues dissolve with different solvents - eg some with metho and other with turps, and the other will not have an effect. Maybe try those two, and then acetone?
