On 9/7/2018 2:33 PM, Nil wrote:
On 07 Sep 2018, Frank "frank wrote in alt.home.repair:

I never heard of obsolete antifreeze. Even saved used could be
used in the winter to help prevent drain traps freezing.

It's Dexcool. It can't be mixed with regular antifreeze and I don't
have that car any more.

I've never needed to prevent drain traps from freezing.

I have friends that do it at their hunting camp and house went left for
a few months in the winter.

Dex Cool is mostly ethylene glycol with a few percent of another
additive. Could be safely washed down the drain.