I had a similar experience...my dishes wouldn't come clean with homemade dish powder, either.
I found a really good deal on super-concentrated liquid laundry detergent...it's in the basement right now, though, so I can't check it out because the cats are locked down there for the night!
But I did the mental math and it costs *less* per load than conventional laundry detergent, and it works well and smells good. Remind me and I will get the name of it!