The residual oil remover mentioned is just a fancy name for lens cleaner that you can pick up in most supermarkets:
http://www.newprouk.co.uk/images/ROR/ROR%20data%20sheet.pdf
I've used this stuff to clean my SLR lenses (and my spectacles) but just by squirting a small amount onto a microfibre cloth rather than directly.
> certainly not an ultrasonic cleaner.
Yeah, I think I'd rather not be exposing my glasses to the rigours of the sonic tank :)