WHOA!!  I saw a lot of truly hazardous chemicals on a recent
shell-cleaning post:  Carbon tetrachloride (which can KILL), toluene,
chloroform.... I think these types of chemicals fall into the "DON'T try
this at home!!" category.  The least toxic, and the most
"environmntallty friendly" chemicals possible, should be used for any
job - shell-cleaning included.  If the safer substances fail to do the
task, one whould perhaps ask just how important cleaning shells really
is- ie, is it worth the risks involved with using very hazardous
materials!?
                                                                                                        Safe-not-sorry in Canda,
                                                                                                        Ross M.