If you also read the testimonials of these people they also say they float. Real gallstones do not float, they sink. Secondly most of the "stones" are way larger than the bile ducts are capable of expanding. You cannot force a basketball through the eye of a needle.
This also brings up the point that it is possible to force a real stone in to the bile ducts if real stones are present. If a stone gets lodged it is going to require emergency surgery. It is not worth the risk. There are simple and safe ways to prevent or dissolve gallstones such as bitters and lecithin.
As far as differences, this is easy to explain. What other cholesterol sources are the sterols reacting with? Cholesterol from food? The chemistry of the other sources can easily alter the texture and color of the sterol-cholesterol complexes. And particles will get trapped in the formation, like insects getting trapped in amber.
If you look back through the liver flush forum someone posted they actually had the "stones" tested by a lab and they came back as not being real gallstones.
As far as feeling better, ingestion of any dietary oil is going to contract the gallbladder preventing stagnation of the gallbladder provided the hormones are in balance.