TL;DR: Use all of these- F R' F', B' R B, S R' S', S' U' S,
Hey! I'm not too experienced with Petrus, I just decided to do some solves with it today, and I'm anywhere from 20 to 35 seconds. It's really fun, I'm going to keep doing Petrus speedsolves! Anyway, during the solves I tried to do everything as efficiently as I could, my 2x2x2 blocks are sometimes only 5 or 6 moves, but I noticed that my EO stage was pretty inefficient, requiring upwards of 10 moves. Now, I had a goal in mind to figure out how to improve the EO step. It's inefficient because I realized I was only using one sequence to solve EO, F R' F'. Now this is good and all, it flips the UF and DR edges, but I was doing setup moves.....
Eh this story is getting too long I'll just give you the algs already xD
F R' F' flips two, UF and DR. - B R B' flips two, UR and UB.
S R' S flips four, UL, FR, UR, BR. - S' U' S flips four, DR, UF, UR, UB.
Petrus pros, what do you use?
Edit:
Making a list of all EO algs for Petrus. Includes Pyjam's algs and anything else I find right now:
F R'* F'
B' R* B
S R'* S'
S' U'* S
D' r U* r' D
r U' r' U2 r U r'
F' U* F
f R* F'
*= turn can be clockwise or anticlockwise.