I'm told the original sealant was putty turned to a paste with boiled linseed oil, rubbed into the gap, and the gap rubbed closed to force out the surplus.
Cyanoacrylate adhesives/superglue may not be poisonous, they are used for medical proceedures. Frinstnce, in China they are injected instead of a cut-and-tie vasectomy. Uhhhh.