Here are my thoughts 1. 2L is too small. I think 3L works about as well as 6L, but you'd need to change the cleaning solution more frequently. 2. From within the US, I'd go with something in the $100-$150 range from Amazon. The brand doesn't seem to matter much; they are all pretty much the same. I would strongly recommend looking for a unit with a drain valve at the bottom -- mine doesn't have this and I really wish it did! 3. TSP for sure. Oxi-Clean defeats the purpose of an ultrasonic cleaner. 4. 30 seconds to 3 minutes, depending on what type of chip you're cleaning and how dirty it is. Lightly used RHC are super fast; super-grimy LCV take a lot longer. Keep the temperature around 100° F or 40° C -- otherwise you risk damaging certain colors. Watch out for pinks and purples, especially. Water that is too hot will fade them permanently. 5. I like to presoak chips in room-temperature water, just to get them wet and start softening the bigger chunks of grime. Don't use heat or detergent on this step. 6. Yes, lots of rinsing. I like to lay out about 20 on a old towel, pat with a towel to get the big drops of water off, then lay them out on another towel for 24 hours or so to let them dry fully.