ok so DUH we all have jeep cherokee's and yeah DUH they all have leaks of a sort of another and finding a GOOD leak stop is hit or miss... I really have only had luck with like three stop leak deals... and the saying goes you get what you pay for...
Anyhow I will toss in my few succes stories and if anyone has a story to tell about the same application having FAILED please post that as well it helps to eliminate DIFFERENT kids of leaks...

So the MOST common leak is a coolant leak... I have found that if you cannot FIND the leak that "alumaseal" works great... I have a three core radiator not sure of the makeup wether brass or plastic but I gave this stuff

a shot and it worked GREAT however I found out that my OTHER leak was due to my mechanical fan making contact with the radiator and thus poking a hole in it... THAT SUCKS, BUT I found a great fix for that
its called quick steel and I guess its most like JBWeld but already mixxed you just have to knead it together and apply it...

I bought this at auto zone for like 3 bucks and I used about 1/4 of this stuff for the hole... basically I just smushed it into the fins where the coolant was leaking from ( it set in water as well) then once I got a good amount on it I killed the motor and let it sit for a few hours as directed and WOW it TOTALLY stopped leaking!

as some of you guys know a few weeks ago I rearended an 18 wheeler which wreaked havoc on my steering gear box seal... it was draining out not DRIPPING but DRAINING... anyhow after a few days of bionic steering methods I decided to a money back deal with Lucas oil on the power steering stop leaks... knowing the reputation Lucas Oils has I could NOT pass this up

They come in two sizes of bottles and after reading the directions I opted for the larger 32oz bottle as it stated two applications MIGHT be needed
Anyhow I tossed that stuff in the other day in the FREEZING COLD and came to find out where my BIGGEST leak was... the cap had TINY cracks in it... it was seeping out of the cap literally... not the SEAL on the cap but from the top where it has the writing on it, Anyhow I drove it to work and back with the whining noise diminishing which was a good sign and especially in the cold I thought just wait for the steering to get difficult again... it never did, Im on day three now with ONE application of the stop leak and my jeep isnt whining and the steering is smooth again and not a SINGLE drop on the ground now... I am astonished...
As for Smoke issues and the "smoke be gone" sealers... I had to use this once on my first XJ and I opted for the literal smoke be gone brand
I cant find an image for that particular brand but this one is just like it

it worked good enough to pass california emissions so Im good with it
Anyhow those are my succes stories now lets hear YOURS!