The DIY Modgepodge doesn’t work - it dries white, and doesn’t hold. Modgepodge is a glue, sealer, and finisher. So yes water down school glue and viola its Modgepodge? You’re logic is flawed. Yes it might be great for a kids craft that you’ll throw away in a few weeks. But any decoupage project you want to look nice you’ll do yourself a favor and do it right. A couple of others don’t work - the best thing to clean windows is water. If you have the time to make stuff at home go for it but the majority of this stuff you would have to special order or go out of your way to find. I don’t have time for that.