Will usually go away on it's own in a couple of weeks in an otherwise healthy dog, but does anyone have any experience/recommendations with vitamins, herbs, or other home remedies?

Nope.
Just with antibiotics.

A vet can vaccinate against it.
I got Trap done because of exposure to other dogs at hunt tests.

Mine was vaccinated too, but he still got it. The vet has him on antibiotics. She said they've had a bunch of cases in the last couple of weeks.

Hate that Sh*t. had an outbreak two years ago where dogs were catching it without even leaving the back yard. It has been proven that the virus can travel up to three miles on the wind. The vaccine you give them is only good for the Bronca Septica Strain of bordatella. The other six strains are relatively unaffected by vaccination. However all the varieties are treated the same with cough suppression and dicloxacillan if they spike a fever. The two dogs that I had cultured had something other than the Septica strain but they came out of it ok.

My dog had it last year. The kennel gave me antibiotics free of charge.

At the first sign of kennel cough my dogs go on dicloxacillin.

When traveling on the dog truck to tests all the dogs are started on vitamin C and Tetracycline (I get mine from livestock supply) prophalacticly 48 hours prior to leaving and throughout the trip. I won't risk my dogs to people who don't care for theirs.

The fact is no matter how careful you are with your dogs health, if you trial/test them or hunt them around other dogs sooner or later they most likely will catch kennel cough.

It took much longer than a couple weeks for my dog to recover.
There are some supplements said to help but it has been so long now that I can't remember what they are.