I personally do 5 on and 10 - 15 sometimes 20 off before root development. If I feel like our it looks like things are getting dry I adjust time intervals. After Roots start I may or may not adjust, just depends on how everything looks. There are a lot of variables like type/brand of cloner, time of year, where you are, where the cloner is, ie basement or attic, etc. If it's cool and I can keep the res temp in check I might just let the pump run continues for a couple days at the start of cloning a batch.
Best I can tell you is don't over thing it, BTW I get told that a lot like almost ever day. Keep your cloner clean and don't throw a bunch of stuff in the res before roots appear, I've used straight clonex or nothing but ro water for years. Only time I have issues is when I don't clean good enough.
Just don't boil the stems or roots and you'll be fine, and after a couple "cloning runs" you will get the hang of it.
I don't use rooting hormones but rooting hormones definitly work.
BTW I found a very short cloning video by permaclone on YouTube. It's the recipe your looking for. Also I read a couple of his blog posts on that permaclone site, I think they are a good read even if you don't agree with everything said.