  Presently clearing electrodes are being considered as a possible cure of
e-cloud driven problems in existing and future colliders. 'Invisible'
electrodes, made of a thin highly resistive layer pasted on a dielectric plate,
have been proposed as one of design solutions for the e-cloud clearing. For the
first time such electrodes were successfully used in the electron-positron
accumulator (EPA) of LEP. Similar electrodes had been using for a long time for
ion clearing purposes in the DAFNE electron ring. Theoretical considerations
and experimental measurements at DAFNE have revealed a substantial contribution
of the ion clearing electrodes (ICE) to the machine broad-band impedance giving
rise to several harmful effects degrading the collider performance. In this
paper we discuss the impact of the electrodes on DAFNE beam dynamics, show the
results of ICE wake field and impedance calculations and compare them with
available experimental data. We also describe the procedure of ICE removal from
the wiggler sections of the electron ring that has resulted in remarkable
improvements in terms of beam dynamics and geometric luminosity.
