For my roggenbier, I use 10% rice hulls per pound of rye. I use malted rye for about 50% of the grist. I still get a slow run, but it doesn't get gummed up. Take your time and let it run slow...****ing (blowback, cleaning the line, etc.) with it will not help like it will with other mashes.
I'm going to try a beta-glucan rest with my next roggenbier.