Clearcasting is still exactly the type of proc the OP spesifically asked to avoid. I'm not opposed to RNG, I kinda like Roll the Bones for example. It's still a valid question and starting to complain about the role of RNG or about someone wanting to avoid RNG in a thread like this is pointless.
As others have said destro is decent for this although 1 of their azerite traits gives a proc to make incinerate instant, so hard to say whether you'll like it or not. MM hunter and WW Monk are, I think, excellent options here. MM can proc either 1 or 2 stacks of a buff as a part of their rotation which brings in some variety but not really a feeling of... losing control. WW has the proc for a free Blackout Kick, but that basically amounts to just a bit more freedom in how to spend your chi since it doesn't really change when you press the button.
There are other specs, I'm sure, but those are the ones I've played on the beta i's expect you to like. Also shadow priest is extremely non-proccy, but they aren't in a great place currently and with the 8.1 rework I wouldn't be surprised at all to see some RNG proc being added to the mix.