Household
Weed Killer
1 Gallon White Vinegaar
1 TBSP dish soap
Mix and spray on weeds.
This is effective because vinegar is an acid. Acetic acid, from any source, will kill most vegetation because it draws all the moisture out of the leaf.
Reference: http://www.garden-counselor-lawn-care.com/vinegar-weed-killer.html
Window Cleaner
1 Cup White Vinegar
3 Cups water
1 tsp dish soap
Pour into sprayer and shake gently to mix.