I had to look up both the character and the English word.
The translation is literally accurate, but "blanch" is an uncommon culinary term, and likely unfamiliar to most English speakers. It means to cook something (usually vegetables) in boiling water for a short time, immediately followed by being chilled in cold water.
Updated
Also a newer euphemism for 肏 ("fuck") on the (mainland) Chinese web, replacing 操 (deprecated) and 草 (now meaning "lol" similar to Japanese use), in the ever evolving euphemism treadmill of Chinese swear words partly to evade censorship.