I have a decent ultrasonic tank, but rarely use it, as it takes forever to heat up and also leaves weird white marks on my pieces that then need re-polishing out.

I find a mug full of boiling water, left to cool for a few minutes, and washing up liquid, put silver pieces in and leave till the water is just about cool enough to stick your fingers in, then a bit of a scrub with an old soft toothbrush removes pretty much everything. I've also found that Luxi and Menzerna polishes are far easier to remove than rouge and tripoli.