Clozaril is usually used as a last resort when other antipsychotics have failed, due to it's side effect profile but is supposedly pure gold in its effectiveness of treating schizophrenia, although I don't know much about it's effectiveness for treating bipolar disorder.
Cognitive confusion and memory loss are potential side effects of Clozaril. Sometimes this can improve over time but it depends. Best to discuss this with your psychiatrist and they can see what to do from there.