Hey Glofishy:
Actually, I realized that I never did actually address the question of this thread so here goes. This is my "valid" alternative although I am not saying that JWs (yet) consider it to be valid. You, or rather your husband, must realize that until things change there are NO VALID alternatives to whatever the structure is or whatever the expectation is.
Even if your husband is engaging in informal ministry or otherwise accruing and "reporting" hours on his monthly service record, if he noticeably fails to support the formal door-to-door work of the congregation or his book-study he will a) get a "talking to" b) get "encouraged" with great frequency, c) never be "used" in any capacity within the congregation, d) may be ostracized informally by others and e) labelled as "weak" having a "Bad Attitude" or being "worldly" etc. etc.
So your husband should understand that from the get-go. If he doesn't mind all of that and just wants to serve Jehovah and feel good about his own conscience then I recommend the following:
1. BE AN EXEMPLARY PERSON. BE THE BEST CHRISTIAN AND KINDEST PERSON THAT HE CAN POSSIBLY BE and BE JOYFUL.
If he can be such as best as he can, and just simply try to let his "light shine" then there WILL BE others who find him attractive and WILL ASK him "hey why are you like you are?" "why do you have so much joy?" etc. etc.
2. THEN WHEN SUCH ONES ASK HIM OR APPROACH HIM, THEN HE WILL HAVE AN OPPORTUNITY TO "WITNESS" to the person. He can do this by either inviting them over to your house to sit down and discuss it, to just set up a regular time to discuss it, or by offering to go visit them at their house.
You might show your husband the footnote to Acts 20:20 in the New World Translation REFERENCE BIBLE VERSION and point out to him that the Society correctly references the REAL translation of the Greek words there as to mean "IN THE HOUSES" not "house-to-house". In other words what you would be pointing out to him is that what the disciples did (upon occassion) was to actually visit and discuss the scriptures/teach about the Good News IN THE HOUSES and not house-to-house/door-to-door. (That is just silly, the disciples never worked end over end, visiting each house, the way that we Witnesses do today.) They taught in the synagoues, in the public squares, and when they found someone willing (like Paul and Cornelius) they went into the house and taught them and that is what your husband should learn to do as an alternative to door-to-door ministry.
-Eduardo