I've always rinsed my dishes no matter how 'clean' they seem to be from a cupboard. I've noticed the residues and a certain slippery feel under water. I rinse them until they are no longer 'slippery'. This could be a rinse aid or it could be bad rinsing of a detergent. Either way I figured it's not a good idea to ingest detergent or rinse aid.
With most dishwashers, if I take a freshly 'washed' class out and fill it with water, I can see foamy bubbles all around the edge of the glass which stay for a while.
If I then rinse it a couple times and try again, I see a few bubbles which quickly dissipate.
