I know very little about dishwashers except they have a trap in the bottom that has to be cleaned occasionally.
I have had the same dishwater for nearly 44 years and have had no problems with it.
She also does the cooking etc.
There must be something you can use to clean out the waste pipe probably a small dose of soda crystals might do the trick maybe used once a week.
No doubt someone that has a dishwasher can give you the proper information that you need.