Nothing truely special about either one. Purchase your local suppliers encap "shampoo" and save on the shipping. They all work.
When Releasit first came out it was made to be used via the Cimex or any other shower feed system. At first I dont think it was made to be used through a fine tip sprayer. Stop being so cheap and buy a Cimex....cleaning with a diaper on your 175 and a spray bottle hanging off your belt loop is not the way to go.