I took some great advice on here and got Shoe Goo for my toe drag. Several thin layers will build up a good barrier that will last a few rounds. It will wear away, but you can keep reapplying.
Another great piece of advice is to buy shoes with a warranty. My Eccos are guaranteed for life.
Check out some construction adhesives. They come in various styles but cheaper than shoe goo and work better. Liquid nails is VERY tough.