I'm not clear whether you used the cheater bar to tighten the body into the crank, or to later remove the crank.

Either way, penetrating oils may or may not help because they're more effective on corroded threads than ones mechanically jammed. When threads a re jammed, the threads distort. This can also happen when great pressure is exerted when the spindle is pushed out. The best bet, if it's practical, is an impact wrench, who's jolting action does a better job on torque jammed threads than steady torque.

If you only used the cheater bar to remove the crank you have another option, which is to use a soft face or deadblow hammer to drive the remover body in toward the crank, hoping to unjam a distorted thread. But this won't help if the remover is already jammed against the bottom by being tightened with the cheater bar.