Tar soap and even shampoo and shower gel is still extremely popular in Finland and Russia, especially for when washing after a sauna. Very specific smell. I hated it at first, felt like I was washing in creosote, but now I've come to quite like it!
I know someone who did this in an emergency after running out of dishwasher tablets. "My kitchen looked like an Ibiza foam party, and my dishwasher got completely clogged up - not a good idea".
How can it be an emergency? If you have washing up liquid then just wash the item you desperately need in the sink and forgo the dishwasher for one time until you go to the shop. I’d understand more if they used some random cleaning thing as a punt if they had nothing else but washing up liquid is literally sold as the thing to hand wash your dishes with.
I squirted the fairy liquid in the dishwasher, shut the door, popped through to the living room, returned 10 minutes later to find my kitchen looked like Narnia.
Yes, that did cross my mind! I only found out when I ran out of dishwasher powder just before a big dinner party, and posted on Facebook that I was considering doing the same thing!