Where should you dewinterize?

[JerseyB1G]

Newbi here...should I dewinterize at home and have flushed water drain into both black and gray tanks? Or....should I wait until first camping trip of Spring season and just hook up city line at campground and drain tanks to sites sewer hookup?

[CloudDriver]

I winterize with the RV antifreeze method. The antifreeze stays in the piping all winter. This coming week I plan to dewinterize at home by partially filling the onboard water tank then use the water pump to run water through the piping. I open the faucets, inside and outside shower one at a time and collect the antifreeze until the water runs clear. I dump the antifreeze, which is non toxic, down a sink in the house. The little bit of antifreeze in the section of piping to the toilet winds up in the black tank. I then sanitize the entire fresh water piping system with the standard dilute bleach solution (1/4 cup of bleach for each 15 gallons of water system capacity). I let the solution sit for a few hours then drain and refill the water tank and water heater and flush the dilute bleach solution out of the piping system. The dilute bleach solution gets drained onto the driveway and winds up in the street storm drains.