ceremonial vessel
豋 refers to a ceremonial vessel, a specific type of ancient ritual container.
豋 is an ancient character depicting a ceremonial vessel. The modern form visually contains 豆 (a ritual vessel) at the bottom, which fits its meaning, but the exact historical development of the upper part is uncertain.
The bottom component 豆 is an ancient ritual vessel. The upper part looks like a lid or decorative top. Picture a special ceremonial vessel with a distinctive lid used in ancient rites.
For トウ, imagine a ceremonial vessel shaped like a toe (トウ). The vessel's lid has a toe-like curve, making it easy to remember: toe -> トウ.