Factoid: "snuck" and "drug" have in common that the irregular conjugation is the non-standard one, but are different in that "snuck" is a neologism of the 19th century whereas "drug" is in fact the older standard form, gradually supplanted by "dragged."

I'd consider Vonnegut a more legitimate measure of proper usage of English than a dictionary or grammar textbook.

Today's popular usage often is tomorrow's proper usage.

Even if it is sometimes a bit unfortunate.