Will deleting from %INC really free much memory? For example, will it free storage space for strings and subs created by the module when it's required? Or does it just free the storage for the filename itself?
You're probably right ... which is why a later response pointed out removing some of the global symbol table. I'm hoping someone who knows the guts of perl better can help out there, but meanwhile, searching @INC is definitely safer and faster and uses less memory :-)