Bloodletting is not a really a helpful thing......
Most of the time it's just making things worse. 😅
Sucking the poison out of a wound is also not something you can really do.
For a manga that's named Genius Doctor the medical practises are terrible. 😕
Magical medicine and inner ki power cultivation miracle cures aside, why would you include a medical practise thats been proven to have no helpful short term benefits at all 😰
( regularly donating blood witch is a kind of bloodletting actually have long term benefits like reducing blood clotting and stuff, but its not going to make you less sick in any way short term)