I have done almost no research in alternate methods of "activating" aluminum, however, I think you would use gallium metal (solid but melts at 30-something Celcius) and not galistan which is an alloy between tin, indium and gallium I think. Also, it would not technically be an amalgam as an amalgum contains mercury, it would simply be an alloy. As far as I have heard the alternate aluminum activating alloys are sketchy at best with varrying alleged results from our fellow clandestine chemists. would advise not attempting this unless you have time and money to burn as I assume you are using this for a redam of mdp2p or p2p. furthermore, read up on a lot of the patents to do with gallium replacing mercury in activated aluminum reactions as they are not 1;1 clones of aluminum amalgam reactions. Best of luck and I would love to know about some of the things you find out.