Here is what I have been using. Stolen from another post or forum, I don't recall.
96oz Oxygen Cleaner (I found a dye free at Dollar General)
4lb TSP
40oz Seventh Generation Dry Automatic Dishwasher soap
That's the same ratio I used. Here's a more thorough thread on the topic for those interested:
For all the time that goes into finding a PBW substitute, is it really worth it? I get PBW for $3.10 a pound thru a local nano-brewery. ($155.00 for 50 lbs.) Which I ended up working at. No mess, no fuss. I have tried the substitute version but in reality you use more of the oxy based version than the real thing.
It doesn't take much time to source three ingredients, and even then, not everyone has the option to get it as cheap as you and/or wants to buy 50 lbs of it at a time. The homebrew version of it ended up costing me just under $2/lb and it works quite well.