How to make cheapo Roundup

Some parts of the yard are sprouting weeds, so I looked online to see if there's a cheaper and safer alternative to Roundup. There's a ton of recipes for weed killers, and this is the one I tried:

2 cups vinegar
1/2 cup lemon juice
2 Tbs dish soap
2 Tbs salt

Yes, salt is bad for the soil, but try to spray the leaves of the weed and grass should grow back quickly.

Does it work? Well, here's some pics.

Before:
12 hours later:
48 hours after spraying:

Roundup is about $10 a gallon, but this recipe makes a whole lot more for less cash. I like it.