I have read - dozens of times, about "pi"ing type, from my research on 1875-1923 newspapers. Here is the latest example I just read from the Silverton Colorado Democrat-Herald of August 15, 1885, Page 3, Column 1, and I think this adequately defines what ye seek:

"He is a sanctimonious printer who will "pi" seven lines of type and never swear about it. He works in the Democrat-Herald office."

Clearly, to pi type is to place it into a state that would make one swear. This would be a jumbled mess that would then need laborious sorting as each letter must be examined to determine what it is and then placed in the proper bin. Then, in this case, the type must be reset by the printer.

I have never seen a reference to a "Hell box" as described above, but that sure makes sense, especially when the young boy that was stuck with all the messy jobs in a print shop -- including sorting type, was called a Devil... and clearly he would spend a great deal of time "in Hell."