Glad to have you here in the QuickBooks Community, @valhallamanageme.
I want to help you record your journal entries in QuickBooks Online. You can add line items to JE's anytime without clearing the registers. May I know why you want to clear an item by the way? This might help me share some tips with you.
I've added here some articles about journal entries below.
Please visit us again if you have other concerns with creating journal entries or any other features in the program. All the best.