Set aside the sarcastic "question with a question" responses, thanks for the information folks!

Yes Anchell suggests that you should not try this with t-grain films which makes sense considering their improved latitude out of the box.

Nicholas- interesting and informative reply, thanks. Anchell doesn't suggest this is to be used to offset reciprocity failure, he indicates that film pushed 2-3 steps will benefit from greater shadow detail using this method. Most importantly, and why I am thinking about trying this at all is the part where he indicates 'the results are grainy but have a unique quality that often complements low light photography aesthetics." This is very interesting to me as a lot of my subjects are in this environment but not limited to long exposures at night with slow "traditional" films (e.g. efke/adox).

Thanks!