Yes, I play with balloons and have fun. :D
The long skinny balloons actually don't seem to work very well for me. The rubber is too thin and they break too easily. A long "dirigible" shape party-balloon works better, I find. You want the balloon to be considerably larger than the amount of water you are going to use, so you aren't fighting the tension in the stretched rubber.
I like to only partly fill the balloon with a bit less than a quart of water, let all the air out, and then tie a knot at the neck to close it. Then on the other end I twist a walnut-size piece of the the end off from the main part of the balloon. Well lubed, I work this part into me. Then, keeping hard pressure on the rest of the balloon, I let it untwist, and force the rest of the balloon and its water to sort of flow up inside me. At this point you have to push hard so it doesn't pop back out instead.
It gives a very interesting fat full feeling in the rectum. I have had no luck so far getting one up higher in my colon.
Different temperatures are interesting. Don't use any temperature you wouldn't use with plain water, and keep the whole thing very well lubed. Although Vaseline will quickly deteriorate the thin rubber,a good quality balloon will hold up long enough to let you enjoy it for an hour or so.
If it pops inside its no different from an enema, but be careful, it makes a helluva wet mess if you pop it outside of you!