I've had shooters at my club tell me they have been shooting,usually a pistol or revolver, for several years and have never cleaned the gun. Furthermore they don't know how to even field strip the gun for cleaning. Some of the newer pistols,Glocks for example, are very forgiving of this type of abuse and will run with no maintenance for quite some time. I've bought guns from people inexpensively who claimed they didn't work. More than once all the gun needed was a good cleaning to put it back into operation.
Jim