I have white smoke coming out of my exhaust. I've tried Bar Leaks, K-Seal and on 1996 Mercury Cougar

Blue Devil. What is the problem none of those worked.

Asked by for the 1996 Mercury Cougar
I say bad head gasket! Have a combustion leak test performed to confirm.
Most any repair shop can do this. And it leaves no doubt as to weather it is a head gasket or not!!