Think of a Tok as a prototype for the FAL. They both tap off LOTS of gas to run the thing and VENT what they don't use.
If your brass is being destroyed, your rifle is USING too much gas and needs to VENT more; that's what the gas adjust is all about.
Port Pressure is the secret here, combined with duration..... just like a steam engine. Slow, heavy bullets and slow powders are a recipe for high port pressures. Fast powders and light bullets (as loaded in most military ammo) give you lower port pressures, especially if the gas port is 'way to hell and gone out in front, as on the Tok.
Just vent more gas. You need the gas-port adjustment tool.
As to wrecking your brass, just how bad is it? If it's just a dented case, go ahead and resize and reload the stuff. It will blow out in the first 1/2500 of a second after you squeeze the triggers, sealing the breech once again as the thing builds pressure and blows the bullet down the barrel. Your brass seals the chamber at very low pressure levels. A dented casing is no great hazard, just as long as it isn't completely crushed.