I am not an accountant, financial advisor, banker, stock broker, forex trader,
attorney, or a member of any other profession that might qualify me to give
advice about money. I am a parent, but that barely qualifies me to give advice
to my kids.
I can't promise you the plan will work for you, nor how much you might save. How much change you generate, so you will have funds to add to your DBSP account, depends on how much and how often you spend. It also depends on how disciplined you are at keeping yourself from spending the restricted denominations. How much you manage to save and not spend depends on your personal situation and how much self-discipline you have.
While the DBSP has worked for others, myself included, there is no guarantee it will work for you. I see no reason why it wouldn't, but if I were to make that a promise, then as sure as I'm sitting here processing oxygen somebody would discover a way for it to fail.
On the other hand, you didn't pay to learn and/or execute the plan, so the worst that might happen is that you don't save anything or spend everything you do save. Experiencing a loss by following this plan stretches the imagination, but I suppose anything's possible.
Nonetheless: The DBSP comes with no promises, guarantees, warranties or assurances, express or implied or imagined. Follow the plan at your own risk.