I think I found a pretty decent spot to farm Sen + Xp + Pellets + Lump Of Fat Wax

[Indie_Kickz]

The "Flower Viewing Stage" Sculptor Idol in "Fountainhead Palace" has an enemy 15 feet behind it through some doors. The "Bell Demon" combined with the "Mibu Balloon Of Wealth" nets +130 Sen,+530 Experience, pretty often drops a pellet and almost 1 out of 5 times drops the Lumps of Fat Wax upgrade material.
I haven't made it further then this so I'm sure there is better farming spots elsewhere but this one is working really well for me!

[✚ Mariel ✚]

Mibu village with demon bell is amazing, the enemies there are scrubs and after you clear each portion you can camp the 2 spawn points killing them before they even finish standing up. Whirlwind strike is amazing there.