You don’t have to test it on your friends; you can test it on your enemies, or on bystanders you don’t care about, or in Voldemort’s case, on minions you don’t care about.
Get a random wizard off the street (if you’re Voldemort) or a prisoner you’re going to kill anyway (if you’re ethical). Control them by Imperius, Legilimizing, or plain threats. Have them make a Horcrux. Kill them and activate the horcrux on a second person you’re willing to kill. Test the result. When done, kill the second person and destroy the Horcrux.
Harry thinks it’s because making a Horcrux for someone else pattern-matches “teaching your most powerful spells to others”, which pattern-matches “helping others altruistically”, and Voldemort has an ugh field around that concept, or at least a blind spot. For what it’s worth, Voldemort agreed with this analysis.
You don’t have to test it on your friends; you can test it on your enemies, or on bystanders you don’t care about, or in Voldemort’s case, on minions you don’t care about.
Get a random wizard off the street (if you’re Voldemort) or a prisoner you’re going to kill anyway (if you’re ethical). Control them by Imperius, Legilimizing, or plain threats. Have them make a Horcrux. Kill them and activate the horcrux on a second person you’re willing to kill. Test the result. When done, kill the second person and destroy the Horcrux.
Yeah, that’s why I said “we don’t have a good explanation why Riddle missed this idea anymore”.
Harry thinks it’s because making a Horcrux for someone else pattern-matches “teaching your most powerful spells to others”, which pattern-matches “helping others altruistically”, and Voldemort has an ugh field around that concept, or at least a blind spot. For what it’s worth, Voldemort agreed with this analysis.