Okay, 47% meterless in the corner with no jump in.
b2u3, f23, f23, f21, f212 xx db2u
The timing is really tight though. Wouldn't suggest doing this other than to style.
Attempting to do this off of a b12 starter now.
I've been doing a variation of that combo for slightly less dmg but I guess it's easier to land.
b12/b2u3, f23, f23, 111, 111~db2u 42/44%
Also as Primiera said, off of b2u3, f23 crosses up and messes up your input, but it only happens if you do it too quick. You gotta slightly delay the f23 after b2u3. The b12 starter is a lot more consistent from my experience since you don't need any delays.
edit: not sure if any of these have been posted or not but here are some more practical variations of the meterless corner combos.
b12, f23, f23, 111, f212~db2u 44%
b2u3, 2, f23, f23, f212~db2u 44%
b2u3, f23, f23, f23~db2u 44%
b2u3, f23, f23, 111, f212~db2u 45%
b2u3, 2, f23, f23, 111, 111~db2u 45%
More meterless corner combos:
b2d3, db2u, f21, f23, 111, 111~db2u 47%
b2d3, db2u, f21, d2~bola, walk forward, nj2, 111 vortex 34%
b2u3, b2u3, b2u3, d2~bola, walk forward, nj2, 111 vortex 33%
b1~db2u, f21, f23, 111, 111~db2u 46%
b1~db2u, f21, d2~bola, walk forward, nj2, 111 vortex, 33%
b12, f23, d2~bola, walk forward, nj2, 111 vortex 29%