Originally Posted by fromelette

(if this is something stupid, please tell me, I always thought this is how it should be done).

This depends on what people you have as friends. Less HP means easier to kill, but also means less EP rewarded. If your friends are capable of downing the SEG, no matter the level, using the Sexual Energy Drink means less EP for them. If your friends will be struggling to kill it (or if you want to attempt it yourself), the Sexual Energy Drink may be a good choice.