Does this also work when taking pictures with characters inside? I have the hardest time getting my camera to take a picture inside at Disney and usually it is showing me the flash icon.
Depends on the relative "newness"/sophistication of your digital camera. Some of the newer models, even the consumer-level ones, are offering things like custom ISO and/or exposure control, and that's often what you need for these kinds of shots.
Let me preface this by saying you should
practice this with your camera and see what kind of results you get, because each camera is different. Caveat photographemtor, or something like that
If your camera supports it, experiment with pushing up what might be termed "ISO Equivalent" or "ISO Rating" on your camera in increments from about 400, to 800, and even as high as 1600. Each of those ratings gives you a better chance to capture something in low-light situations with less or no need for a flash. In fact, some cameras have a specific "no-flash" mode.
Be aware that there's a trade-off as you push up the ISO, because as ISO increases, so increases the risk for what's called "noise" or "grain" in the background of the picture. Some cameras have built-in "high ISO noise compensation" for precisely that reason. Keep in mind, too, that any ISO noise is magnified as you increase (enlarge) the picture for printing. The key is to experiment as much as possible with your camera, because every camera has its own variety of sensor and firmware that makes the results peculiar to that manufacturer. Learning the details of your camera can help you get a LOT more enjoyment out of it. I surprised myself taking some Wishes fireworks shots a couple of years ago with my Nikon pushed up to an ISO of 3200 with manual focus and rapid-fire shooting as an experiment. I wasn't really expecting them to be great, but when I looked at them at the hotel that night, I found several had turned out really well, and one of them was so good I blew the thing up and framed it. So experiment, experiment, experiment!
The only other real option is to go the opposite extreme and push the ISO very *low*, like 100, but that's typically only useful for long-exposure shots with the camera mounted on a tripod, and that's not typically how most Disney pics are being taken.
Hope that helps!