Ultrasonic Cleaner For Bicycle Parts? Watch Before You Buy! (Vevor 3L Ultrasonic Cleaner Review) 

Make sure you never have parts directly resting on the bottom long term. It can wear holes over time in your tray from the metal on metal contact. People over hype ultrasonic cleaners for everything, for big uniform surfaces you have better tools like a parts washer full of mineral spirits and some brushing after letting it sit. But they are great for small details and tight crevices and as a final cleaning pass for uniformity. Its important to remember like dissolves like, so to remove grease you want a non-polar solvent. Water is a polar solvent. That is part of why Goo Gone works so well on grease and adhesives, it contains glycol ether compounds which are non-polar solvents. Undiluted Windshield washer fluid works well too, though use rubber gloves when handling it. Degreasing is all about your solvent, ultrasonic cleaners are just an alternative to a brush but should never be the 1st step when getting you have lots of filth. Though it is hard to beat for final degreasing with chains, put it in a mason jar with mineral spirits, ultrasonic cleaner just takes then from an overnight wait to a 30 minute wait.

i have to ask is all that easier than parafin wax

Using a device what's it's not intended for is kind of stupid. You need to degrease those BEFORE you put them in there, otherwise you will have to refill it and do a second wash. That grease messes up the cleaner that's why you need to only use Ultrasonic cleaning solution by itself. Why you have other cleaners there, I have no idea they're not designed for this. Next time use the product as intended to get the results you are expecting.