I have heard that putting your feeder directly in water can wash off some of the scent, making it less appealing to your snakes, though I guess some don't seem to mind it. I put mine in a ziploc bag in hot water to thaw it, with the top sticking out so it doesn't leak. I'm also going to be trying the hair-dryer trick just before I feed it, to make sure it's actually warm enough. As long as it's not left out too long, I think refreezing once is ok, but any more and I've heard it can start to break down. If it seems too mushy though, I'd just toss it. Better safe than sorry when it comes to your snakeys.