How much water are you giving it? I guarantee you are overwatering.
It is pretty hard to kill clones.
My method (100% success rate so far, 7-12 days to root):
- Cut a clone wherever the hell you feel like it, at a 45 degree angle
- Dip in roottech cloning gel
- Place in rockwool cube
- Keep cube moist, but not wet
- Clip off the tips of the fan leaves
- Mist & Dome for the first ~3 days until they can survive without the dome without wilting.
It's very common for them to wilt slightly the first 1-2 days, they will come back.
If you use rockwool, DO NOT squeeze the cubes. It is necessary to maintain the proper moisture/air ratio that rockwool is designed to optimize. Air is as important for root growth as moisture is.
I'll generally take the dome off on day 3 and see roots by day 7. Varies a bit by strain, and will vary based on your individual environment.
EDIT: I almost forgot, I also have my cloning domes on top of seedling heat mats. Heat underneath promotes root growth as well.
EDIT2: I'm also running a few side-by-side tests right now, plain water VS diluted nutrient solution VS water + SuperThrive.
It looks like the SuperThrive solution is doing the best, but I won't know until I see roots pop.