This Corcom filter sound like better idea. It is basically a common mode choke. When you wind two wires, hot and return, on the toroidal core it becomes common mode choke. Such choke presents inductance for common mode signals and no inductance for normal mode signals. It is because in normal mode current flows in both wires in opposite directions and each wire induces magnetic flux in the core in opposite direction. Magnetic fluxes cancel and choke has no inductance. For common mode signals induced electrical noise current is the same in both wires, fluxes add up, and choke presents inductance (hence reactive impedance). The other advantage is that for normal mode (differential) currents choke will never get saturated, since induced magnetic flux is zero.
You can also make simple common mode choke by winding few turns of power cord on large toroidal ferrite.
You can also make simple common mode choke by winding few turns of power cord on large toroidal ferrite.
