Take them out of your freezer the day before freezing and place them in your refridgerator overnight. . . Longer process initially, but when you go to use them that afternoon you will find they are quickly warmed up. . .

When I thaw out Large to Jumbo Rats, I usually just thaw them out in a bucket of warm water. Change the water every 30 minutes, and it should be thawed within an hour or so. It takes "longer" but its more hands off which makes it go faster for you since you can multitask while you take care of other stuff. Some people have issues using wet rats, but my snakes love em.