The government will have little influence over the French imports. It will be people complaining to their local stores and restaurants that will have the most effect.
If you tell a restaurant that you find it offensive that they are pushing French wines after what France has done lately, and that you have decided not to order any wine in protest, you are doing more for the boycott than you can imagine.
If you tell your local grocery store manager that you are going to buy your groceries at his competitor because he stocks Evian or Perrier then you will have an effect.
And of course if you refuse to buy any French products yourself you will have an effect. Each action is really only a tiny drop of water in the big scheme of things, but put enough drops of water together and you have an ocean.