JEMman, what I have always done, and I may have it bassackwards, is flush for a couple weeks and superflush one last time. I would let the plant stay in the soil until the soil got dry from that point. Then, cut and start dry/cure.
I have taken it without the final big flush before and it didn't make a noticeable difference. But, when I'm flushing for two weeks, I'm flushing... not just watering with no ferts... I try to run water through until it is pretty clear.
The reality is, it's not going to taste like poison if you don't take it the exact right day. Heck, I doubt I would be able to tell the difference. I mean, sometimes we start acting a little bit like the discerning cigar connoisseur who " tastes the hints of chocolate, with a little woody background, finishing with a nutty ...bla-bla-bla". LOL Heck! I've smoked lots and lots of cigars (I mean lots)... all the best, some from the best cigar makin' country. I have never tasted chocolate, I'd throw 'em away if they tasted like wood, and if I want some nuts, I'll get a can! LOL
Man, you grew some great herb. If you're stressing over trying to let it go another four or five days, stop stressing and get the hay on into the barn.
That's Dirt's
P.S. About how fast the plant is drinking the water... That hasn't got anything to do with the plant being ready. All that means is the root structure is utilizing the resources available in the pot faster. Your roots are still growing.