How do I contact local retailer

If I am getting you vis a vis 'local retailer', you can easily pin point a good retailer in your city & I feel it may need not be a garment/apparel trader if you are concerned with publicity only & that too for a limited period.

You can thus choose suitable location & store where you find the best of your target audience are suppose to shop. You can yourself ask the retailer directly & any progressive minded retailer won't mind to assist you with your Eco friendly products I suppose.

On business side you can offer him/her dealership if suits to you/retailer & most importantly to audience; afterward. Also you can, if its feasible for you, ask him/her a shelf or similar retail display space offering him/her benefits like many FMCG & other brands do. 

And yes, you should have posted it in Q&A section,,its not a debate.