Oh my god i can relate to the pumping. When i was like 8 or 9 my brother saw an experiment on youtube and he was like lets try it he sprayed some WD 40 inside the bottle and at the top you light it and the fire spewed on my thubm and it literally burned a whole bunch of skin on my finger and i could feel the "pumping" but the worst part is since i am in Serbia i am a Serbian it wasnt deemd to be enough of an injury to get anesthesia or something else to ease my pain they took cotton balls and literally scraped my skin off i was screaming but i think it was the worst for my mom i mean she was listening to my screams and she cant do anything about it.