I've finally managed to implement an install-free version of my utility to check for bind variables usage. The new script is named bvc_check.sql and when run, it examines the SQL statements stored in the library cache (through gv$sql) and dumps the ones that would be the same if the literals were replaced by bind variables.
An example of the output:
------------------ statements count : 0000000003 bound : select*from t where x=:n example 1: select * from t where x = 2 example 2: select * from t where x = 3 ------------------
So we have 3 statements that are the same once literals are replaced with bind variables. Two examples are provided; the action of replacing the literals 2 and 3 with the bind variable :n makes the statements the same.
The script are available on this page, that also explains the script workings in more detail and describes other scripts that might be of interest.