In my experieces since leaving the Witnesses, I always direct them back to the "inspection" period and make them take a long, deep thought about what they are claiming in todays "present truth." They state that Jesus sat down on his throne in October of 1914 and for the next 4 and 1/2 years looked down upon the earth to see who was doing Jehovah's will.
A group of workers known then as International Bible Students were the only ones who had kept on the watch and had declared 1914 as the time of his return.
The problem is that they were not "on the watch" because they had believed Jesus had returned in 1874. According to this group, Jesus had been back for 44.5 years when he supposedly selected them as the faithful and discreet slave in the spring of 1919.
And as he selected them, they were in the midst of creating even more false teachings which they continue to do to this day, i.e. millions now living will never die, Armageddon in 1925, in the "remaining months" of 1941, 1975, the generation of 1914, etc.
I still amaze myself that I was able to revel in such delusional thinking.
Donny