Buy some silicone lubricant spray. You can normally get it from auto stores or hardware stores. Make sure you get one that drys.
When you get you wig, before you get it messy, spray the pigtails with this spray. Do it outside because this stuff makes everything it touches slippery. Make sure it get though the strands thoroughly. Let it dry, brush it out. This spray will help to stop the friction that destroys wigs. Keep a little brush on you at the con and if you in line or sat down, brush your wig.