The case is obvious: dishwashers cost money and energy but a kitten's tongue is free.
Here we have Kai and Xena demonstrating the dual action plate cleaning technique.
Remember that as soon as you've cleaned the plate, you must sit on it. Otherwise how will your human know that you've finished? Although, strangely, some humans do not seem to appreciate this. And may make references to 'are those the same feet that just came out of the litter tray?'
This is, of course, a rhetorical question born out of envy - humans only having the two feet and never having mastered the litter tray.
Below we see Xena getting into position on her plate and doing a last minute check before sitting up and signalling her task complete. Meanwhile Kai is manoeuvring his tongue into all those difficult-to-get-to places that human hands and pan scrapers never quite manage.
Remember, raspy kitten tongues are far more efficient than pan scrapers - which should be removed from the human's sink and ripped to shreds. A process that is both helpful - pan scourers being the work of the devil (I am told they are manufactured by forced kitten labour in third world kennels!) - and fun. Ummm, shreddy goodness.
Below we see Xena demonstrating the kitten approved sitting position for signalling the plate is 100% kitten clean and ready to be put away. Kai, meanwhile, has found a patch of extra sticky porridge. This may take some time.
Finally we have Kai and Xena cleaning the sink. Note the vertical tails. Vertical tails, besides acting as an excellent counter balance, signal that traces of milk have been detected and humans are advised - for their own safety - to keep their distance.