Once you have decided to proceed with the sexual nullification of your slaves -by penisectomy, castration, permanent chastitization, or any other method- it is advisable that they are ordered to masturbate for the last time at the sight of your body. Submission psychology has demonstrated that, if the slave knows in advance that it will be nullified, this simple procedure readily creates in the mind a permanent bond of awe and admiration to the owner's physique. Many of the slave farms that perform nullification are equiped for the "last-time operation", with individual vertical slave cages and a raised platform for the owner -since it is important that slaves look upwards at Master as they have the final masturbation. You can rent these facilities for a relatively low price, provided that the slaves lick the ejaculations clean when they are done. Ask your favorite farm for their rates!