You can buy a bottle of Citric Acid in the canning section at the store. If it has a cleaning cycle start it then wait a while to add the bottle of citric acid as some dishwashers do a prewash before it starts the long hot cleaning cycle. If I were you I think I’d buy at least 2 bottles and run 2 cleaning cycles. Then once a month there after

We used the DW Magic or similar product and it took several loads to get the "taste" out of the machine. You noticed it with glasses, which made water poured into them taste strange for many cycles. It did clean the inside of the machine though.

Lemi-Shine dishwasher cleaner and heaviest soil cycle. Put it in the main detergent dispenser and not just the prewash detergent indent.

Houzz user, you didn't cite the brand/model of dishwasher involved. May be necessary to disassemble some of the pump for access to clean otherwise-hidden areas of it. Dishwasher cleaners are well and good for what they can do ... but they're not always strong enough to clear very heavy grease/muck accumulation, which may need some direct-access scrubbing.

If I found foot particles in my diswasher, I might do something more than buy Citric Acid.

(JK, my Houzz oopsies would fill a small dictionary.)

Do a google search to find the maintenance directions for your machine. As mentioned above, there are all sorts of hidden areas for gunk to hide.

Another place to look for icky buildup is in the spray arms. The maintenance directions will show you how to remove them - it is usually to spin them counter-clockwise.