There is no device or filter which will remove low order harmonic distortion from the power line short of regeneration of the AC (and even this has it's problems).

The best way to solve the DC problem is to run the AC hot lead through two back-to-back electrolytic capacitors (negative-to-negative) of around 10,000uF (or more) and about 200VAC rating. I wouldn't try this at home though unless you know what you're doing because these voltages can be hazardous.