If you run out of regular dishwasher detergent, can you just use the hand-washing kind instead?
Nope, confirms This Old House's Richard Trethewey. Not unless you're itching to clean up a decent-sized mess both inside and outside your dishwasher.
The problem is that these two dish detergents work very differently, according to the Handbook of Detergents. Sink soap is very sudsy because the detergent is doing the cleaning. Machine soap is much less sudsy, because high-temperature water is doing most of the work.
At the same time, all those suds from sink soap can clog up the fine inner workings of the dish washer, meaning you'll likely be doing some wet-vac work to fix a soapy overflow, Tretheway says.
See the results of such an experiment in the video above. Find more from This Old House on their YouTube channel.