Question About Bleaching Needles

it leaves a nasty mark even if you get the barb off? like what i'm thinking now is i could maybe sharpen under a magnifying glass, get it as close to new as possible, just keep doing that until the needle gets bent or whatever, unusable. i have taken everyone's advice and gotten a couple sets of backup works but still, if i'm going to do something grody (e.g. sharpening and reusing needles) i want to be as informed as possible so that i can minimize damage. so, if you sharpen it up, where you have a nice point and no barbs, it'll still fuck your veins?

i do use syringes twice most of the time, but no more often than that. once they have their two shots done i cut the needles off and keep the syringe part for plugging or doing shots of whiskey. probably not in that order.