I don't know a whole lot about homemade shampoos. But I am pretty sure there are store-bought shampoo options that are not P&G or honey based.
I use Beauty Without Cruelty. I believe they are vegan and not tied to P&G. Here is their website if you want to look into it
http://www.beautywithoutcruelty.com/ I think you can buy right from there or through sites like drugstore.com They also sell it at my local grocery store. It's a tad pricey, but it's not outrageous. It works well, and the bottles are fairly large.