you want to break your DB a curious way?
have a look at v$system_fix_control and v$session_fix_control and gamble by change the parameter _fix_control. I also found _fix_control_key but no information about it.
For more than one patch to switch, use
alter session set "_fix_control"='4728348:OFF','4663698:OFF';i learned here.
What is it good for?
To test if the just-applied patch works as expected.
Patches are to fix bugs. Playing around with bugs is a job for exterminators.
Happy playing ;-)