First of all, so-called cannot be used as a verb, as in your first example; it is an adjective.
Secondly, so-called is used for two possible meanings: first, to give a "popular name" for a thing that has a different "proper name", such as
the so-called 'splat' character (that is, the asterisk: *)
Or it can be used to indicate that you are going to refer to something with a name that you think is actually an improper or invalid name:
my so-called friend just told the teacher I cheated.
(You are referring to someone as a friend, but the use of "so-called" indicates that you think that their behavior demonstrates that they aren't really your friend.)
Thus you should not write your sentence with "so-called" at all. Use "called" to inform people of the proper name of the technique.