As long as it's not ethylene glycol, it will be a heck of a lot easier
on any barn cats that might be around. Cats love anti-freeze and it
kills them overnight.

BobH

Milady LOVES cats. They won't touch ethylene glycol with soluable oil
and other junk in the coolant. For my 2 cents, I'd go this way, but
the kid is with you, he won't use old radiator coolant like I did
years ago.