my apologies, it appears you dry the organs with them. here's 2 guides with pictures
http://www.angelfire.com/biz/piranha038/proj_pira_mummi.html
http://www.monsterfishkeepers.com/forums/showthread.php?179055-preserving-my-12-quot-tern
http://www.monsterfishkeepers.com/forums/showthread.php?274578-My-mummified-piraya
http://www.angelfire.com/biz/piranha038/proj_pira_mummi.html
http://www.monsterfishkeepers.com/forums/showthread.php?179055-preserving-my-12-quot-tern
http://www.monsterfishkeepers.com/forums/showthread.php?274578-My-mummified-piraya