Just in passing, when I want the WTS to read something, to make sure they do, I always send a "copy" to the local congregation. That's to assure it will get the attention it is supposed to. Otherwise, I think someone screens everything and just dumps "aposstate" materials in the trash or send it back "unread." They also will suggest that you contact the local elders and try to work out answers through them first before writing the Society. Of course, that way, they can control you better.
Of course, the WTS will know if you're legitimately asking a question or lecturing to them about some false teaching you think they have.
Now what I used to do to get a message out to the witnesses was to write the WTS a letter bringing up some topic, pretending to be concerned about correcting some false teaching. Then I'd send a copy of that letter to every congregation in the United States! It takes about $300 in stamps I think to send a copy to every Kingdom Hall. You can use the library and get a list of all the Kingdom Halls in every state and a program will arrange the name and address in a label form. So all you have to do is cut out the addresses and glue them on to an envelope. Just as a bit of trivia, about 1/3 of the letters will come back because I guess a lot of Kingdom Halls are in rural areas and they use a P.O. Box for the mail and not the address of the actual building.
Anyway, I was a bit devious. If you send something to the PO then he'll likely just chuck it as "apostate material" after he gets into it a bit. So what I'd so is send a copy to "Attn: Literature servant." The person opening the mail for the literature department likely thinks it relates to some book order or something. Plus usually there is a ministerial servant in that position a lot of times. So he will open the letter addressed to the WTS. He'll be distracted since the letter is directed to the Governing Body and the Writing Commitee, thus this is not something that appears to be trying to be hid from the headquarters. Your target group, of course, are the local elders. They are responsible for screening things and making decisions about apostate materials, etc. But if you send it to the literature department, then he won't know what to do with it and so will show it to some other elders. By the time they figure out it's apostate information, even though a letter addressed to the WTS of which they are just getting a copy, it will be to late; they will have been infected with the concepts of the letter. The other advantage is that even though they realize this is likely apostate material, they have to report it to the headquarters just so that headquarters know that there is apostate male being sent to the local congregations.
But, of course, I really wasn't asking a question to get information, but to point out an error. For instance, in the parable of the vinewyard workers, ALL the workers get the penny so all go to heaven. The WTS identifies themselves as the 11th-hour workers who are murmured against by the earlier 1st-hour workers, who they say is Christendom. So I'd write a letter not contradicting this but asking, "If the WTS is the 11th-hour workers, and the 1st-hour workers are Christendom who murmur against them. Then who are the third through the 9th-hour workers who also get the penny?" Of course, I know full well they don't have an answer. Plus even though the 1st-hour workers murmur against the 11th-hour workers, Christ still gives them their penny that they have earned--they just don't get anything extra as they expected.
Anyway, as noted, usually they have a good answer for most questions. If it is something they get stuck on, they figure you're borderline apostate and they may not respond at all or sick the local elders on you.