I clean my dryers vent hose and vent every 2 months. I take the hose off and vacuum all the lint out of it.
It only takes about 30 minutes to pull the dryer out, remove the dryer vent hose from the dryer and vacuum it all out and then put it back together.
It's a good idea to get that lint out of the dryer vent because it can potentially cause a house fire if not cleaned regularly.