Worth noting that the Devil's algorithm is not a sequence of turns you repeat over and over, but one that takes you through every possible cube state. You "abort" it partway through when you reach your desired state.
It is both: it is a sequence of turns that if you repeat them over and over, will take you through every possible cube state. But it is possible that the shortest such sequence is trillions of moves long.
There are 43 quintillion cube states, so "trillions" is understating by at least a factor of 10^6.
I'm not sure if the 43 quintillion are reachable in a loop of that many moves, or if you need to backtrack through some states to reach others and thus need more moves than that.