There wasn't any other way to increase commissions much when I was there. The cap for solo sales was 15%.
On the other hand, selling home security systems door to door, which I also did, did have a performance based pay, which was 10% initial and would go up to 50% plus bonuses to top sellers. And it only went up via sales, not recruitment.
Maybe Cutco found the MLM tactic to be more profitable since you had to buy your own demo sets.