[svandamme]

to do what? what do you want to clean with it?
How dirty are the things you want to clean?
how many transducers ?
how big is the tub (physical size and Liters)?

to put it in perspective, if you have a tub that is 20cm W x 30cm L x 30cm H
with 2 transducers

And you want to put in a part that is 28 cm long.. well.
You'll have a part that is somewhat clean in the middle.. and to clean the edges you'll have to reposition the end in the transducer range... then do the same for the other end.

Transducers don't clean throughout the tub, they mostly clean right where the transducer is.