Like you, I had many cloning failures as I got started (I'm still getting started, but finally have something that is working). I tried aeroponics, water only, water with clone solution, soil with clone powder, soil with clone gel, pods, etc.
The first thing I found is that you can't assume one strain will clone the same as another. Once I got a system down that works, I had roots on all of my Chocolate Hashberry in 7 days but my MAC and Big Mac took 2-3 weeks. The big trick with those that take longer is keeping the balance between rotting the stem and drying out. Aeroponics rotted everything before it had a chance to start rooting. Putting pods in the pod trays made it too likely that the pods touched the water below, making them too wet and they rotted as well.
What I found that is working for all strains is using a tray designed for rockwool cubes to keep the pods from touching water and being able to see the water level. I also invert the pods so that the wide part is at the bottom. This allows you to easily see roots as they appear, as well as making it simple to pick them up to look or move them.
I take all of my clippings longer than they need to be and place them directly in water, then do a cloning process later. Slice off the lowest node flush with the stem, cut your 45° through that node space, lightly scrape the stem just above the cut, dip into clone powder, dip into clone gel, place into clone pod.
Clipping the tips off of the fan leaves also helps keep them from getting too much energy from the light. We want the leaves to help keep the plant alive long enough to get roots, but we also need the plant to want to grow roots. I presoak the pods in a water and
clonex solution, giving a good shake before cloning to get some oxygen in there. I leave them under a 24/7 cloning light on 1/2 power, but have an unplugged heat pad (you could use a towel) over the dome to prevent the direct light. I burp two or three times a day and use a straight water mister to wet the inside of the dome each time. Sometimes a pod may start to dry a little, so I will use the mister on that pod just enough to get it about 1/2 soaked.
These Big Macs got a little fried when I forgot to put the dome and shade back on.
Triple chocolate - I think it would root in a mud puddle. Super easy to clone.
This is my dome covered to prevent the direct light before I plant the successful clones into soil.