Some existential questions: Where do you get aphrodisiac ?.
Even if you get the good ending to the lizard tribe, can you still capture Roushk?
Can you use the love position to get bernard or logan?
Sometimes, the potion can be learned by studying back at home.. but:
Aphrodisiac: Water lilly + Blue Essence + Succubus leaf + [empty] + Green Essence
capturing Roushk only happened when Othra asks you to get him.. whither you are going bad or good route for the lizards.. however, i havent tried the bad route lately.
"get" as term of them loving the MC and increasing a heart, no. for the time being you may use the love potion on the Bartender, Shopkeeper, blacksmith or Filiar to have a scene [if you know what i mean]