I agree with Arthur that most people that post on JWD are ex-JWs and even when they were going to JW meetings, they put little if no time into going door to door.
Some JWs deal with the harassment from the elders re being inactive by turning in the minimum required 1 hour, usually phantom time. Then they gradually cut down on the number of meetings attended.
Many non-JWs ask about going door to door because they are not aware of all the ways JWs can circumvent it (as some posters outlined above).
I went to meetings for ten years and avoided door to door in various ways because I could not invite anyone to come to the KH and be treated in the unloving way I was. Actually, I talked non-JWs that were studying with JWs to stop studying...can that be called nonwitnessing? Many use only the Bible and never offer any literature. I even know of some who make it a point to work alone and then never knock on the door or ring the bell.
Believe me the JW that comes to your door and tries to get you to take their publications or have a bible study are not the ones who don't believe any longer. The ones that actually do make return visits and get you to have that "doorstep" bible study or are constantly inviting your to come to the KH are the ones who are the "true believers."
Once JWs realize that it is not "the truth" it takes time to develop an exit plan. I'd be the last person to set a time line for anyone.
Blondie