You don't have to use it, as the machines still have the option to use normal dish washer tablets. But if you want to use their auto dosing feature (in theory it works out how dirty your dishes are and does only as much detergent as you need), then yes you're locked into their proprietary system, and paying 2-4 times as much per wash.

You can toss a spoon of powder into any dishwasher before pressing go.

Stockholders are all about the after-sale subscription model.

The convenience outweighs the cost at this point. I'm not proud about it.