Some companies charge variable rates (currently 5-7%) some fixed (6-8%). This interest rate is paid back to the insurance companies annually. You pay back the principal in your own time frame.
If you want to pay a loan back with extra interest, then that “extra” interest goes to your cash value in the form of a PUA (paid-up additions) contribution. Your gross cash value continues to earn the dividend, unaffected by the loan, offsetting the impact of the policy loan interest, but not “netting” it. These are 2 separate accounts, cash value, and loan.