Ok, so I know this is not edible, but it IS still a recipe. . .
Save up those detergent bottles, and when you run out, try making your own detergent. Here is what I did:
grate (finely) 1 bar of Fels-Naptha soap ($0.97 at Wal-Mart). Other lightly scented soap can also be used (body or laundry--another laundry soap I saw is Zote)
1.5 c Sodium Carbonate (pH plus or Washing Soda. Cannot find Washing Soda, so I used pH plus from the pool chemical section. It is 98% Sodium Carbonate and 2% Water. $5.97 at Wal-Mart)
1.5 c Borax. ( I believe it was $3.97 at Wal-Mart)
boil 3 c water in a large saucepan. add grated soap, whisk well. add sodium carbonate. mix; add borax, mix again. pour into a bucket and add about a gallon of water (more if you want it thinner, less if you want it concentrated. I simply did this amount because it was the combined capacity of my bottles). If you add about a gallon, use one ounce per load. It must be shaken before each use, as it will separate almost immediately.
I figured out that this costs about $4 for 120 loads. a lot less than you pay for Tide