It really is important - and I can't stress this enough - that you don't spary alcohol directly onto the hair. That would be bad. Alcohol is the number one killer for hair systems; it dries the hair up and, over time, you're left with an unusable head of straw.
As Martykay mentioned - a good oil based adhesive solvent is the way to go. Or, if you don't have access to one and you need to do this asap, use a good shampoo, then run a system-friendly conditioner through it. You know those combs you they use on children with head lice? Get one! You can pick one up at the supermarket for very little money. Use it to comb out the conditioner/oil-based solvent, and the excess glue.
Good luck
THG