JW's will use every possible method in an effort to reach you. If that means attempting to communicate with you through other people, they will. They know, at least subconsciously, that it puts both you and the other person on the spot, but, hey!, what are friends for???
There is little you can do to stop the JW's. The thing to work on is your communication with your husband. If possible, find a way to let him know that no matter what JW's attempt, you do not want it to interfere with your relationship with HIM. Let him know that is what's happening, that JW's are beginning to poison your freedom of speech with HIM because you are concerned about what they will do in their attempts to "regain" you. Invoke his protection! It would be better if he recognized, on his own, the need to keep all family matters private, but in the event that he does not yet see through their manipulation, ask him if he would please refrain from discussing anything at all about the family or about your beliefs with the Witnesses. Tell him that you made yourself clear to the person at the door and that there is nothing further to discuss. You availed yourself of their offer to learn more, you aren't in agreement with what you have learned and you determined that it was time to stop the interaction.
Are these JW's paying your husband to work for them? Or is it the usual case of latching on to someone and getting work done "free"? Be careful about that. Even if the work is paid, the aggravation may negate the value of the money. You might be able to reason on it this way: you lived without the work before you met the Witnesses, you can live without it again. Speaking from collective experience here, the work will more than likely dry up when they see that neither of you are interested in "The Truth".
It's going to take some time to completely rid yourself of the JW clan. The next time a Circuit Overseer comes into the area they may even bring him (or his wife) around to "invite" you to his special talk or to rekindle a discussion or the study. Be on the watch.
Be polite but stand your ground. Don't give "reasons". Just say NO.
Nina