Does anyone use ultrasonic bath to clean razors?
I do.
For many years, I've been playing and restoring melodeons, and I bought a 2 litre heated, timed stainless steel workshop-grade ultrasonic cleaner for cleaning steel and zinc reeds and reed plates. It can be used with a variety of cleaning additives for different metals, although washing-up liquid does as well as many.
In time, of course, I started to use it for other things, so it gets a turn at razors, the old girl's jewellery, spectacles, glassware, vintage and modern fountain pens, cycle parts, odd tools etc.
It will shift all "dirt" on razors, but, for most of them, especially 3-piece, it's just as quick and easy to use the soap/toothbrush method, followed by Peek or similar. Where a bath comes into its own is cleaning butterfly razors, and particularly adjustables, as it will operate on the dirt inside the razor and its internal mechanisms. Previously I'd soaked these in various solutions and for different periods, but the bath does the job more efficiently and quicker.
Perfectly good baths for domestic use can be bought for less than £30. That may not make economic sense if you only want to use it for razors, but, as I've tried to show, they can find a multiplicity of uses in the home.