One problem with using regular wrenches to remove pedals is clearance. The wrench has to be pretty thin. For years I used a very thin cone wrench I happened to have. It was very short so tough to get torque to loosen, so I would smack it with a rubber mallet. Finally, I broke down and bought a pedal wrench from Performance, I think it cost $10.

But if you can find a conventional box-end wrench that will fit in that space, go for it. There's nothing magical about pedal wrenches except (1) the thin construction for the clearance and (2) a nice long, rubber padded handle so you don't kill your hand.