The difference is your application won't last long and actually weakens the plastic so it will tarnish faster. Our product is guaranteed to last several years and strengthens and seals the plastic and protects it against UV rays from the sun. There is no guarantee with the products you are stating and if you mess up someone else's by way of your recommendation will you repair/replace their headlights? I didn't think so... Our product is patented and is used by thousands of dealers across the nation. And there's a reason why they use our product. The choice is yours - buy a product with a guarantee and thousands of satisfied customers, or go with questionable advice, ruin your headlights and buy another set - hmmm Thats about $400+ for two headlights - wow what a saings $-394 and see if the person whom gave you this recomendation will cut you a check for that $394 you are in the hole. I think its a simple decision.