Thanks everyone for all your answers.sounds like the my cubes retaining to much moisture is my problem.
You'll notice that if you let the cube dry out a little more, it'll start rooting right away, assuming you've been going for over a week or so already. its no different than your plant, wet and dry are bad, damp is good.
This thread is great in that all the info previous posted is spot on. Here's some detailed explanation, some may be repeat.
the humidity dome is key, a well spend 2 bucks....i wouldn't skip that....in some cases when you finally take it off, you will have to acclimate the babies to drier air with time on time off after rooting.
heating pad...mandatory in cool temps and you should have it it warmer temps too but its not 100% mandatory in the summer
I like gel cause it seems easier but both gel and powder have the same hormones in it.
Misting plants allows the plant to take up water, they have no roots so they are absorbing it through the air. Always mist, your temps in rh will dictate how much you need to
Rockwool and rapid rooter are a personal choice, they hold water at different levels so try both and pick what you like.
Rapid rooter have very large holes so if you are cloning very thin stems, you'll need to split the cube so you have some contact with the cube.
I've cloned inch long shoots before, anything with a growing tip will root but its easier to work with if its a bit longer, i've actually also seen foot long clones with pencil width stems at oakland dispensaries.
You should try to be as sterile as possible when cloning but i never follow that advice, I usually use my trimming scissors that are dirty with resin that won't come off...but again you're not supposed to...risks infection.
After cutting, do your scrape and dip as fast as you can because air entering your stem can cause problems, this may be a wives tale but go fast anyway just in case, won't hurt.
I've also read that splitting the stem up an inch helps them root faster but this may be false, never tried it personally. Maybe someone else can chime in on this that has tried it.
Whitetrash style.....A shoot will also root with no hormones, no dome, no pad etc....straight in a glass of water than you change daily, not the ideal way to do it but it will work if someone reading doesn't have access to any of the supplies. Stick some plastic wrap across the top of the glass and hang the stem into the water.
Important point....when throwing the clones under a HPS or outside, make sure you acclimate them to the light, indirect HPS 4 feet away or in indirect sun otherwise they'll collapse.