I used diaper cream as a gasket sealant for a thermostat housing gasket that I cut out of something. It worked surprisingly well.
We were on a trip to Oregon. 30 years ago. Wife, baby, & me in a 69 Mustang 351 coupe. It drove fine around home in traffic or at freeway speeds, but on the long run it began overheating. I pulled the t-stat in the hope it was the cause. Ended up being a partially clogged radiator that would flow enough for dd work, but not quite enough for the long haul at speed. We figured out that it would stay cool at 50 mph, so we limped along & got there. Had the rad re-cored in OR & it ran great for the trip home.
Once home I replaced the t-stat. The diaper cream never leaked & was so easy to clean up that I considered using it again. Not for long though. Gasgacinch won out.