According to a study, it is midazolam and temazepam that are most often used in date rape among benzos. The link is below.
However, all benzo's are highly soluble in alcohol, so flunitrazepam is not special in that way. It is not a "date rape drug" - benzos have the potential to be "date rape drugs". Clonazepam tastes wonderful and two tablets of the 2 mg pills (so a total of 4 mg) crushed up and put into some naive person's drink and you get a knocked out individual that won't respond and will not remember the time that he/she was knocked out. This is just an anxiolytic were talking about here - a weak sedative at that too. Any benzo has that potential, some (the hypnotics) are more favorable to commit such crimes as amnesia and sedation tends to be quite stronger than say with something like alprazolam or clonazepam.
Alcohol remains to be the #1 date rape drug in the world, but of course, we don't hear about that. GHB is used to commit such crimes more frequently.
According to research conducted by Michael Robertson from the San Diego Medical Examiner's office and Dr. Mahmoud El Sohly of El Sohly Laboratories, test results indicated that flunitrazepam was only used in around 1% of reported date rapes according to Robertson and 0.33% according to urine lab tests done by El Sohly. The benzodiazepines midazolam and temazepam were the two most common benzodiazepines utilized for date rape.
That research paper can be found
RIGHT HERE!