X Depthwise

BL - edge FL
LF'L'FLUL'
done as RwU'Rw'FLUL'
BR - edge FR
R'FRF'R'U'R
FL - edge BL
L'BLB'L'U'L
(U)LU'L2'U'LFUF'
from Lars Vandenbergh
FR - edge BR
RB'R'BRUR'
(U')R'UR2UR'F'U'F
from Lars Vandenbergh