Without a doubt is the killing method known as scaphism:
Also known as the boats, is an ancient Persian method of execution designed to inflict torturous death. The name comes from the Greek word skaphe, meaning “scooped (or hollowed) out” and from Latin word meaning “boats”.
The naked person would be firmly fastened within a back-to-back pair of narrow rowboats (or in some variations a hollowed-out tree trunk), the head, hands, and feet protruding from this improvised container. The condemned was forced to ingest milk and honey to the point of developing severe diarrhea, and more honey would be rubbed on his body so as to attract insects to the exposed appendages. They would then be left to float on a stagnant pond (or alternately, simply exposed to the sun somewhere). The defenseless individual’s feces accumulated within the container, attracting more insects, which would eat and breed within his or her exposed (and increasingly gangrenous) flesh. Death, when it eventually occurred, was probably due to a combination of dehydration, starvation and septic shock. Insanity would typically set in after a few days.
In other recorded versions, the insects did not eat the person; biting and stinging insects such as wasps, which were attracted by honey on the body, acted as the torture.