I suppose another way of telling that a person has spent some time in the Halls of Jehovah is the inclination to use the term "fleshly".
Has it occurred to you yet that people do not generally refer to their biological siblings as a "fleshly" relative?
There is the occasional "yes, he/she is my flesh and blood". But even then it is a tad poetic with a hint of snootiness. Yet "fleshly" is distinctly alien, don't you think? And it is a good thing to avoid using this JW jargon. For I have seen this happen in JW circles where in using the word "fleshly" they accidentally leave out the second "L", making it "my fleshy sister"!!
INQ