Usually only expat shops and a few online stores catering to various immigrant (so far only have found British, German, and Mexican) sell laundry products to/in the United States.
You may wish to try Canadian or Mexcian sources that ship to the US. Sometimes they have laundry products not found in the States. Also check supermarkets in immigrant communites. Have seen Asian verisons of Tide locally, but not Mexican Ariel. Local Sears-Mart has several Mexican laundry products, but not the elusive Ariel for front loaders. The rest like Focca and Roma are very high sudsing and have too much scent.
Many detergent makers for other countries just do not want their products sold in the United States due to liablity laws. Thus even if an importer were willing to bring supply in, he may face trouble. Lever Bros actually sued, IIRC won a case against someone importing/selling their products into the US without their permission.
Considering most of the top laundry products all come from about three worldwide mega-conglomerates (Henkel, Lever Bros, Proctor and Gamble)aside from variation for water hardness, type of washing machine, and local washing habits, there really is not much of a major difference between top shelf detergents, IMHO.
Think many of us would like to see more high performance detergents for front loaders, that do not cost a arm and leg over top loading detergents. In countries where front loaders are the rule rather than the exception, one finds entire asiles of all and sundry detergents.
