The requirement of KHBD to castrate oneself is to stop oneself from going berserk from the sexual energy generated.
With ultimate inner energy control skills like Yi Jin Jing and Bei Ming Shen Gong, do you think a martial artist can learn either YJJ or BMSG first, then learn KHBD without castration by converting whatever energy is generated by KHBD into Bei Ming Zhen Qi?
That could be rather cheesy.