Do you let the plane's positive stability (bank) take over to keep wings level by removing your hands from the yoke, and then try to descend after trimming for a slight nose low attitude (trim tab indicator is still going to be visible) while cutting power to idle?
An a/c doesn't really have bank (lateral) stability; it has side slip stability. Dihedral can't detect a bank, it detects the sideslip that an uncoordinated bank will produce.
Unfortunately, there's something stronger than lateral stability....directional stability, which also reacts to sideslip. This is why aircraft are
spirally unstable. If you bank to the left, the directional stability tends reorient the airplane into the relative wind in order to correct the sideslip, rather than level the wings. The resulting yawing motion tends to aggravate the bank, leading to more sideslip and more yaw, etc. This is the origin of the graveyard spiral.
Assuming the airplane was laterally in trim, it may be that a steady descent could get you out of the clouds before before the spiral could get established. I see no advantage to trimming for a nose low attitude....that just increases the airspeed at which the descent would take place. Reducing the power alone would lower the pitch attitude below the horizon, initiating a descent. (Of course, you don't have a horizon for reference, either natural or artificial.)
More to your point, although the lateral stability is low, it may be superior to your trying to manually level the wings, allowing you more time to break out of the clouds during a descent.
For a swept wing aircraft, increasing the AoA (slowing down), will increase the dihedral effect considerably, providing greater lateral stability, possibly increasing the safety of the maneuver. However, these aircraft are the least likely to lose *all* attitude references.