Yes plenty of alternatives for sanitizer but what you are really looking for is a no-rinse sanitizer. You can experiment to find out what works (and what doesn't), what's toxic at what concentrations, contact times, etc but really, why bother when for <$20 you can get a couple years worth of Star San. I'm all for DIY but really just get the Star San. It's a great product. Don't fear the foam!!!
That said, you can use bleach and vinegar mix in a pinch. Search on "no rinse sanitizer" for the recipe.