As far as flushing your system from the injection CYPD26 and CYP3A4 might be responsible for metabolizing the drug you where injected with.
But as stated with a half-life of 19 days at 5 months in it's likely there is no more drug remaining in your system, unless you are unable to metabolize those enzymes/pathways properly.
That being said the doses of these injections often seem to be far outside of normal therepeautic range. One could deduce that the shrinks are loading patients up on as high of doses as they can possibly get away with as a way to increase duration. Doubling dose effectively increases elimination by an extra half life at the cost of overdosing patient and causing more severe negative responses to treatment. For a drug with a 50 day half life this is pretty extreme.
If that's the case applicable inducers may help, probably worth getting blood checked to see if there's any drug remaining in your system before going to effort of trying to flush it out. Likely it's out of your system and inducers come with interactions and side effects.
There's something about reversible and irreversible antagonists too. Some antagonists such as paliperidone will irreversibly bond to the receptors. This however won't be as permanent as it sounds, after your system is clear receptors get recycled and new receptors can grow. Neuroplasticity agents may help hasten this process but it will happen by itself in hours, days and weeks after cessation. Again these come with extra interactions and side effects.
From what I have read it seems that after being on these drugs for long periods of time neurological changes occur, upregulation and down regulation of different receptors, neurons growing in new places, all sorts of nonsense. It goes a bit further than just flushing the offending drug from the system or reversing it's effect, as it's not just the effects of the drug but the neurological changes that these effects lead to that are of concern.
Scene set and setting are pretty important. Psychological changes might be more impactful on one's wellbeing than physical neurological changes. The psychological toll of being institutionalized and being placed on forced treatment may have more of a negative impact on the patient than the neurological changes from the drug.
What are your current symptoms?
I'm not an expert mate, none of this should be taken as fact, just trying to understand it.