Saw a video where a guy used a split pipe clamp with a rubber seal for a steam leak. He tightened it right over the split flange. That high-temp silicone wrap you used is smart for a quick bandage. I keep a tube of that metallic repair putty in my bag for small leaks on pipes, it sets up hard even on wet surfaces. For anything bigger, it's all about getting something around the whole pipe to contain it until you can kill the pressure. Your fix with the hose clamps is basically the field version of a proper clamp seal.