Actually, it doesn’t absolutely have to be PitchFlex.  You can use quite a few of the PitchFactor algorithms for this. See which one sounds best to you.  Generally, they will follow similar settings.  These listed below assume that you don’t want to “flex” pitches.

PitchFlex

• Mix – fully clockwise to Wet
• Pitch Mix – centered
• Pitch A & Pitch B – -m2 or -M2
• Delay A, Delay B, Depth/Key, Speed/Scale, Xnob, Ynob – fully counter-clockwise