Depending on your distance, Rog will be able to punish the blocked sweep with jab > BnB. If you really want the untechable, meaty cl.mp is much better, since you can link into sweep, if blocked it puts you in a very advantageous position and doesn’t leave you free for punish if he backdashes. Also, considering how easy it is to time meaties on him, even out of regular knockdowns, I don’t think untechables are as important.
I think the best OS against him is meaty :df::lk::db::df::mk:~:lk:. It beats every dash punch aside from EX Straight, puts you in block if he EX Headbutts and is easily confirmable out of. It loses to super, EX straight as mentioned, both ultras and backdash outside of corner. Midscreen you can do :d::lk::df::r::hp::d::lk: to catch backdashes, but you will lose to EX Heabutt and the same stuff above.
Remember that his dash punches are not safe and poorly spaced straights can be punished with s.jab x rekka (maybe only the fierce ones, not sure). I focus a lot on this match up, since it’s very footsie based, you can some times catch rush punches and the ones that can break armor are easily punishable. Never jump in on him, since he has one of the best AA normals and the always present risk of heabutt > ultra.
I also like U2 in this match, since it’s a science proven fact that every Balrog will spam jabs like there’s no tomorrow. This is, however, a very personal/preference oriented decision. If you’re pro, you can also OS U2 as :d::df::lk::d::df::r::hk::mk::lk: (all credit to neville in the Lab Findings thread).