Anyone use Final Flush to fertilize up to harvest?

So I just read that you can fert up to the last 3 days if you use "Final Flush" to get rid of the built up chemicals.-Jorge Cervantes
Not sure if this is beneficial in that you can keep giving them food or just the lazy way of flushing?
Any thoughts?

On a separate but related note I am thinking of harvesting in 2 weeks. However, do not have my microscope yet to check the trichs. (it's in the mail) Should I plan on it or wait and see?
I was considering the Final Flush that way I can be in total control of when I harvest instead of flushing for 2 weeks and then not being ready....
Thanks in advance to opinions and advice...

i would use it for one week, then flush with water the last week. you want a purge of everything in the plant.

makes two res changes tho.