I just use Return to Sender and hold the right mouse button to charge it using a full bar of salts, all the while firing at her with whatever weapon I have. She constantly spawns enemies so I just ignore them while absorbing their shots. Once my salts bar starts getting low, I wait for her to stop moving and spawn more enemies, then throw the Return to Sender ball of fuck you damage at her and it takes like 1/4 of her health bar. Become a reflect tank to kill a damage sponge, some RPG tactics in this bitch.
If your aim isn't good, just use a bit of RoS at a time, absorb some damage and throw it back, rinse and repeat. I know she can be a slippery bitch so it does suck to use a full bar of salts and miss with your supecharged RoS.

i beat lady comstock in seconds with return to sender and a carbine

That was Good and Interesting

Thank you I almost threw away like 8 hours of my life I finally killed that BITCH.....

Thanks a lot, I wouldn't have done 1999 mode without this trick (and WInter Shield ofc).

i just select easy mode and spam the luger till she displays her gross green feet on the ground

I HATE this boss fight, I usually only win because of that glitch where if you die enough times she just disappears.

Knowing this glitch is SO helpful

so this is how you beat lady cumsock

I wish I knew this when I did 1999 mode without vending machines

Bro, you're a genius