Put rinse liquid detergent in dishwasher rinse aid compartment.

I did the same thing with my Maytag dishwasher, several times actually, before realizing I was putting blue dish soap in the rinse aid compartment which then wouldn't empty. Then my Maytag started making ominous noises during the rinse cycle (appliance guy said it was "cavitation" noise).

Appliance guy wanted to replace the whole detergent/rinse aid compartment but since he told me the noise was probably caused by the dish soap stuck in the rinse aid compartment, I decided to try to get rid of it first. Here is the method that worked for me; it took most of a day but saved me parts & labor:

1. Get some white vinegar--I used nearly a quart.
2. Fill the rinse aid compartment to brim with the vinegar (overfill) but don't put cap on
3. Raise the dishwasher door slowly until the vinegar drains into the lower part of the chamber (at least this is how my Maytag worked)
4. Agitate the contents as best you can by rapidly shaking the dishwasher door up & down.
5. I also used a small plastic medicine dropper jammed into small openings on each side of the rinse aid compartment to agitate the vinegar by squeezing air into them.
6. Drain the compartment by closing the dishwasher door (move it to full vertical)--vinegar will drain into the bottom of the dishwasher.
7. Repeat above steps a couple times, then fill again w/vinegar, put the cap on and let it stand for awhile. Then drain and repeat the whole routine several times.
8. Blue-colored vinegar will come out which is a good sign (or whatever color your dish soap was).
9. After awhile, I started pouring generous amts of very hot tap water thru the rinse aid compartment, alternating with white vinegar. (No reason you can't use hot vinegar also.)
10. Eventually, all the blue stuff came out & the see-thru levels of the rinse aid compartment were completely clear/empty.
11. Run the dishwasher (I decided to not put any rinse aid in). I got some overfoaming (from the washed out soap) the first time I ran it which I probably could have remedied by adding more vinegar & possibly salt, but the noises were gone!
I just ran the cleaned out dishwasher a 2nd time & it was back to its quiet self with no overfoaming.

Takes some patience but hey, beats a big repair bill!!