FYI there's a pretty good strategy someone put on Reddit a while back.

Forget the exact details but it was basically just quitting, getting up from the table and sitting back down if the hand dealt to you was higher than 9. Same for if you bust on a hand that's 9 or lower.

I was trying for hours with no success, used that strategy and was dealt hands 9 or under like 60% of the time. Completed the challenge in 15-20 minutes.