well you are being a little on the vague side for me to understand, lol. but i am kind of getting the gist of what you are asking.

i am in a field where i have vast amounts of knowledge that i could charge for that i give away for free to anybody who asks and many people challenge me also. i many times make them set up an appt to come into my office to talk to me.

i believe if people are questioning you, vague, isnt the best approach, more like key words that let them know that you have the knowledge they want so they know you know what they are talking about. lure them in. so they know you know your stuff. if you are vague, they will question if you really know anything. so after you drop the key elements of knowledge about their item, then you invite them to your turf to discuss it further. they will want to know more about what you know since you have demonstrated some clear understanding about it already. vague doesnt demonstrate clear understanding.

i hope this helps.