My plumber told us to put white vinegar down the drains once a week.

[dixiegrrrrl]

I have not had any problems with it.
I use in instead of the rinse aid in the dishwasher, use it in washing machine to clean soap scum, use it in dish water when cleaning the pet dishes ( makes them squeaky clean),
wipe the counters and cutting boards with it, spray it ( mixed with water) in the shower stalls.