As the title says: Has anybody tried making your own? For true low melt cerrosafe alloy you need Cadmium as one of the elements, but for "Rose's Metal" you only need bismuth, lead and tin, and the alloy will still melt in boiling water. Rose's metal is two parts bismuth, one part lead and one part tin. This can easily be accomplished with one part bismuth shot (three or four shells should do) and one part 50/50 solder.
I could buy the original stuff, but it's pretty expensive over here.