It’s mentioned 9 times in The Count of Monte Cristo by Alexandre Dumas.
It is mentioned also in several other novels written by Alexandre Dumas, including some where the action happens in the 16th century, by the time of Catherine de' Medici (a time when in reality there have been many allegations that some suspicious deaths have been caused by poisoning).
Therefore in these novels the use of "aqua tofana" is an anachronism, as it precedes by almost a century the time when "aqua tofana" is supposed to have been invented.
Definitely it had its mind share so it was possibly a tad bit overhyped.