Give it time buddy, and after your bleach cycle.. dismiss the instructions that came with the cloner and use plain water. I use tap that comes out around 130 ppm straight from the sink. The bucket has APPROXIMATELY 4 gallons of water in it, and I add a tiny bit less than a cap full of 3% Hydrogen Peroxide from Wal-Mart.. Nothing else I read either online or via the cloning instructions with the bucket worked. It's slow, but it's cheap and I've had my best success rates yet.
I have gotten a slight mildew buildup on some of the clones, I think my bucket lid and inserts need a real good soak and rinse. If I get to it quick I can kinda scrape it off with my finger nail, but I have my new Blue Mystic clone to replace my last mother with a little on it, and I'm hoping it'll just start new growth soon and I can trim those leaves off. You say it's on your stems though which is a bit more precarious I suppose.
Also one other idea, as far as the water chiller goes, test out the cloning in a cooler environment if you can before you make the investment just to make sure it will in fact make a difference in your cloning experience. Either move it into another cooler room's closet under a small cfl or do the ol' frozen water bottle method. Water chillers aren't cheap. I want one myself but I can't justify the cost just now, and I am afraid of overloading my breaker with that, the flower cab and the veg cab on the same circuit. I already have a 6" icebox heat exchanger though once I get it.
Off topic, I wonder how difficult it'd be to rewire one of the 2 outlets in my room to it's own separate breaker..
I want to see you succeed in the cloning arena man, almost as much as I want to succeed myself. I definitely feel your pain!