Is it possible to override a hint by SQL patch?

Hi all,

I am tuning the following SQL structure, which is provided by the application and therefore cannot be altered.

select ... from ...

where ... in  (select /*+ CARDINALITY(...) */ ...)

and ...

;

My approach is to parallel tune the SQL, which has proven successful. The new structure produces a more efficient parallel execution plan:

select /*+ PARALLEL FULL(...) opt_param(...) */ ... from ...

where ... in  (select ...)

and ...

;

Now I am tring to apply the new hint by SQL patch, but with little success. Although the patch is being created successfully and correctly associated with the sql (clearly to be seen in OEM), the old execution plan is still in effect.