Resuscitation of THE Glue Stick?

I found some old glue sticks in the "just in case" cupboard [just in case I might need it at some point :) So, after reading the lesson I sussed them out and they were dry and hard :( Of course, now I know better and I will put the new ones into plastic bags. Still, if these ones I have can be brought back to life you will tell me how to do it, right? Cheers!