Down parry+block on Remy wakeup...there's not much he can do. If you can knock him down in the corner, there shouldn't anything save for wakeup super that could get him out. Train him not to retaliate with flash kicks by being defensive on wakeup, then use

+mp and UOH to punish low block(UOH+SA1 if you know the spacing, nearly a guaranteed low mk+lk tatsu combo on wakeup/ throw). Do alot of crouching short+RH tatsumaki to annoy him. Akuma has way too many tools to waste time on Remy^_
Edit: If you aren't confident about jumping at him don't, especially if you see he has a flash kick charged and waiting. Learn to do Akuma's karathrow, it adds TREMENDOUSLY to his game, and is easy to do. Either people will constantly eat it and get thrown, or they will try to counter throw from absurd ranges, allowing you to low mk+anything. Walk up while parrying the Lights of Justices(????) and keep poking with low mk. Block and immediately throw any CBKs.