Where to find ethers/elixirs

Does anyone know where you can buy elixirs and/or ethers, or are they just randomly spawned in the grottos? I need them for the E4 rematches :3

If this helps u can get leppa berries from the vileplume berry harvest and there’s one in one of the flowerbeds at telnor town


Oh yeah that’s really smart, thank you :smiley: