Silicone sealant, used to glue things in place, needs time to off-gas (irritating vinegar-like fumes). If you put it on thick, it takes a LONG time to dry- so beware!
It's thick, so it dries from the outside, while the inside is still "wet" & off-gassing- be careful how thick you apply it if you plan for it to be usable soon- your snake should never be breathing it. If YOU can smell it, don't expose your snake to it- house them elsewhere if applying it inside their enclosure while it's drying.