Grail is not meant for clean; you can try dialing it way down, but that tone will not satisfy
Clean tone depends on the genre you're going for, the guitar you're using. In general...
the KH1 sounds good out of the box
SuperV has a love/hate following, not a lot of low end there but plenty of chime
Stock BFace, make sure it's a recent version or you will need to modify
Deluxe will work, but it has a country mid flavor that may or may not be your taste
Gigmods has an awesome array of modded modules that are great for clean tones, the Gigmods Tweed is awe-inspiring with a Strat, the GigmodsJTM gets you a wides range of Jimi clean to crunch on a strat and ACDC with a gibson. The Gigmods Blackface is my goto clean, I love it on any guitar. Topboost is solid with the gain on a switch it is the most versatile mod around
Did any of that help?
BTW you better hope that isn't Brock the QB because than you just slammed the guy!