There's no way to cycle 20x without bill-paying your card below it's credit line, creating negative balance. I've cycled many cards, and the fastest turnaround without bank holidays is 3 days, so you can do 2x per week if you just pay only after charges hit the balance. Force-paying it into negative balance territory using BPs is a big red flag with every CC bank. WF used to shut people down for that before they even caught on to the 5x gaming, for example.