2 rockets to destroy a Wooden Wall. That's 2,800 sulfur in raw materials.
1 C4 charge to break a Wooden Wall, roughly 2,200 sulfur plus metal fragments and tech trash.
3 satchels to destroy a Wooden Wall in Rust.
The cheapest explosive option for a Wooden Wall is 3× Satchel Charge at roughly 1,440 sulfur.