Data point. I find when dealing with anything over 50 lines that by adding strict and then correcting the errors that it reports I usually figure out the code faster than trying to read it. Normally in the process I find a few bugs (often including the original one) and if I don't get the one that I am after I have at least learned the code well enough to guess where it is.

Therefore adding strict as part of trying to debug reported problems may be a workable strategy.