I could be mistaken, but I believe tempering is an alternative to rapid cooling- it'll stop graininess when it solidifies for this upcoming use. But just like rapid cooling- when finished product melts and then firms up again- grains.
So, how to avoid grains:
-I've heard butter ez is great stuff. Lotioncrafter has it, and if you call their customer service #, they're really really helpful.
-lotioncrafter has another product that also sounds really helpful. I do not recall the name of it though. I think it was maybe a powder you dissolve in your oils and butters when you melt everything down and either your end product can withstand higher temps without melting OR maybe it instead prevents graininess. I can't remember which. I do know that for my body butter, I seriously considered this stuff and intended to try it before trying the butter ez. So- again, lotion crafter customer service is your friend.
-92 degree coconut oil and high melt Shea butter are both amazing. Yes, high melt Shea is heartstoppingly expensive. At over 25% of my product I use a lot of it. SO WORTH IT. I somehow convinced myself it wasn't that big a deal and masterbatched with regular Shea. Never, ever again.
-this one is odd... avoid rice bran oil for anything where your final products melt point matters. Long story short, I found that when i used rice bran oil instead of sweet almond oil, it lowered my melt point by at least 10 degrees.