If I remember right, ballistics gel is just gelatin mixed with water, i.e. nonflavored jello. Don't quote me on this.
I have seen people use multiple milk jugs filled with water to test expansion properties of water if thats what you are trying to do. The body is like 70% water.
To have actual "official" ballistics gel, it has to be tested once made to make sure it is within some sort of limits that simulate flesh. I don't know what type of equipment is required for that.
Sorry if I just made you even more confused.
Practice doesn't make perfect, it make permanent.
When I hear a Liberal say "I can speak for gun owners because I own a shotgun" I just want to scream "Well I can speak for vegetarians because I like lettuce on my cheeseburger!"