you ain't gonna get massive depth but,
file the bib to get a sharpened edge,remove top part of lure directly above the bib, this will make the bib longer,move the line tie up,the more positive pressure on the bib will drive it futher down, but you'll lose some wobble if not all.
add 1 or 2 sizes bigger on the front treble,smaller line diameter,drop some buoyancy out of the lure.
kev