Here is what I do. I use a program called CeRegEditor which you install on your PC. It will connect to your phone and you can take a snapshot of the registry. I do this before installing a program. Then I install the program and compare the new registry with the original registry through CeRegEditor and it will hightlight the changes for you. You can then export any registry entries that changed or were created. Save those exported entries to import into Sashimi. This takes some time to do but you only have to do it one time for each program. I have also found that I only need to export the registry once and I can usually get away with installing 4-5 apps before I export it again because there aren't that many registry entries that change per program.
CeRegEditor can be downloaded for free here:
http://ceregeditor.mdsoft.pl/