Hey Tav,
Jack is a great strain that really packs it on the last 2 to 3 weeks. It can almost seem like a laggard during weeks 5 and 6. When I grow Jack Herer, I finish on Growth Energy. It has such a powerful smell already, and the GE brings out a sweetness and a really interesting terpene profile without changing the basic smell of the strain. (gotta grow me some more!!) So I wouldn't do a second Cat Drench on Jack.
The reason it's so dang Sativafied is because of the 11/13 photoperiod? Are you doing that? I can't remember. But seriously, the photoperiod and the soil combined is going to really bring out the Thai and Colombian. You're a rich man!
I only like the Cat drench on stuff that is ridiculous, like the WN. I'm gonna try that again someday......and I'm also going to run some Colombian Red one of these days soon. I'll probably Cat Drench one of those when the time comes and compare to the others.
So, about the salty drench, it's like Growth Energy but with lots of potassium. It leeches out pretty well, so it won't permanently ruin your soil for High Brix like Greensand or too much K-mag or some organic material, etc.