or even you may try the same, but without need in creating a class:

oldMethod := MorphicUIManager methodDictionary at: #inform:
MorphicUIManager compileSilently: 'inform: aMessage  "do nothing"'
classified: 'dumb'.

.. run your code..

MorpicUIManager addSelectorSilently: #inform: withMethod: oldMethod


-- 
Best regards,
Igor Stasenko AKA sig.