I am not a expert by any means, but I have had some success (and failures) with my homemade aero-cloner. (a 5 gallon bucket with only 9 sites)
1) learned lesson # 1, the first time you use it, you will have pretty good luck, but unless you really sterilize it, any follow-on uses will have much lower success. At least that was my experience. Scrubbing and then running a strong bleach solution for 2 days before my next use has seemed to cause a increase in my success ratio.
2) temps play a important part, and make it pretty difficult in the summer unless you have a cycle timer to help reduce the amount of time that your water pump is on. Those things generate plenty of heat and will get your water/solution too warm after an few days if they run non-stop.
My success with cloning seems to be a hit or miss, but keeping everything super clean seems to help a lot!
for what it is worth!