This 146 smoke in the air con has been overblown by the press , the fact is that eny aircraft that has a leaking seal in the engine/apu compressor will put smoke into the air con
The answer to the problem is to shut the suspect bleed valve , a problem with a pack is not likly to last very long as the bootstrap turbo compressor only carries about 1 USQT of oil and will seaze up when this is exhusted shutting down the pack likewise if you can determin which pack is playing up by looking at the indications then shut it down.