DIY Enema

For quite some time now, I’ve been keen to give an enema a go. I’ve already tried inserting small ice cubes in that area; they didn’t bother me too much, except near the “Entrance”. Could I use something like a water-filled balloon, pop it into the hole and leave it? Or perhaps a tiny plastic bag with a rubber tube attached to it. I realize there’s risk involved, but would medium-temperature water be safe? If not, what are the specific dangers of an enema?