Slayer doesn't always get 50% or more, especially if he's playing a non-japanese player who is probably doing sub-optimal combos or is trying to do optimal combos and dropping them. Slayer gets rewarded when he has meter, which he'll usually have a lot of, but your confirming skills have to be pretty high to capitalize off Slayer's weaker normals (6K, 5K, 2P, c.S/f.S, etc) on ground hit and not in the corner. You also don't have to always be doing ballsy moves, you just have to play an insanely patient neutral game. Bear in mind that Slayer has 2H and 6P which will destroy you if you rush in too hastily (bear in mind, 6P beats the first hit of any level of rock-it clean). Running in and blocking isn't the worst thing to do, especially if you think they're going to do something high-risk high-reward like that. It's not like Slayer can lock you down after having you block one normal or poke. Also, try to get free charge whenever you can if they're not going in on you.
Honestly it depends on who you're playing, but the chances are you're either playing netplay scrubs or a friend that lives close to you. Just try your best to figure out their tendencies quickly and adjust.
Whenever I was having dinner with CrimsonDisaster and a bunch of other Austin peeps, he told me this in regards to HOS: "The better you are at fighting games, the better you will be at playing Order-Sol." Take that as you will, I took it as "fundamentals are really important to playing Order-Sol" but I think it's simple enough that you could take any message from it.