I found the best way is to use my 2 acc,
And do pet battles.
Run with 2x 25s 1x random lower lvl, match on other acc.
Set up a key simulator, to que on both acc with join pet battle macro,
enter pet battle on both,
click forfeight button -> select 25 pet on main acc -> accept forfeight (had issue were it missed select pet so it leveled up)
then just loop it.
takes roughly 20s a win, depending on loadtime and quespeed.