Which octave pedal is the cleanest & most versatile?

I'm an audio engineer working in a rock studio, often we get asked if there is an octave pedal, and nobody ever seems to bring one when they need it. We have a high strung nashville style guitar to get a similar effect, but sometimes the octave pedal is what the song needs.

I have access to a couple octave-fuzz pedals but they get smeary & I'd prefer a separate clean octave pedal by itself, and choose the best dirt pedal after, if it needs it.

So I'm curious which one tracks the best for this simple task? Pog? Sub-n-Up? Boss OC-5, Super Shifter? Any others? What do you think is the cleanest overall?