I wanted to ask OP how to treat his list of strings.
I know that phrase "mischievousness" is a real brainwallet that leads to address 16t9GqUj2ocEipDEfkrteUTTCXbCK7kJ1q (one SHA256 applied).
I wonder what address has OP derrived from phrase "BoingBoing00" and how he got there. By looking at the code he provided it gives you WIF (5KfhTr87eouEJKS2YFPdHHkdYzUpRwXJYUU4kMe7Knk5vdzfFh4), but the address (16zxUKMDd6eiSb35UJqQbjUvmPTmfzx7km) had no transactions.
Well, you should take some brainwallets, list of passwords, or any other, and convert them to WIFs using my script.
The things here are:
1. You may use SHA256 once or twice on the input data (line of text), once give more hits, twice is the original way which should be used. Usually I use SHA256 once for brainwallets.
2. You may put readable ASCII characters to convert to WIFs or already use binary data in form of SHA256 (32 bytes of any value).
Yes, I got the same WIF from your phrase. Address also. That means there was no transactions for this address, no output, no input. Then the private key is completely empty.