Filtering AC Power to Mounts

I am not sure what the quality of house hold power is like in the US has but if it is anything like what is available in Australia it might be quite poor (just watching the lights noticeably dim now and again is proof if this) and this can vary state to state. My question is do some owners of Equatorial Mounts use an AC line filter to clean the power up thereby improving the tracking accuracy when powering from a household AC outlet or is this just a waste of $$$$. Obviously powering in the field is done via a DC Power Tank or batteries so the power is ripple free.