Electrasol tabs migh work!
Actually, I'm not sure if there was a soap dish. I do remember directions on Cascade that said you could put two tablespoons on the bottom of the tub. On my sister's KDI16 the soap dispenser doesn't work so I use two Electrosol tabs, one at the beginning and then I open the door to add another at the long wash period. Now, my BIL tries to use only one tab at the beginning - you have to use two!. Electrosol tabs would probably work in your Hobart too.