I make this and use washing soda. It is important for the best results to use hot water when using Borax. I like the idea of mixing with a box of cheapo dish washing soap. Thanks for the tip....I will try that the next time.
http://chemistry.about.com/od/howthingsworkfaqs/a/howboraxworks.htm
Although it has numerous industrial uses, in the home borax is used as a natural laundry booster, multipurpose cleaner, fungicide, preservative, insecticide, herbicide, disinfectant, dessicant, and ingredient in making 'slime'. Borax crystals are odorless, whitish (can have various color impurities), and alkaline. Borax is not flammable and is not reactive. It can be mixed with most other cleaning agents, including chlorine bleach.