Hydro also picks up torpedoes. Believe me, unless a DD has nerve, when he sees pissed off battleship bearing INTO smoke he launches torpedoes and scarpers.
If you have high enough RoF (so cruisers), you can blindfire into smoke too. Though that works better vs. British cruisers and Trollotov which hav to go stationary (almost).
TBH, if you are a battleship, best counter to smoke is killing enemy cruisers and trying to catch shels instead of friendly cruisers.