Dominant7b5 chords are hard to make sound good, even in minor progressions (at least to my ears). Given a choice I will usually alter the 5th by sharping it instead, a much hipper sound (my opinion).
They do work nice in chromatic progressions though with proper voice leading, here's the bridge to Superstition by Stevie Wonder;
|B7.C7.|B7.Bb7b5.|A7...|E7#9...||