The £20 versions from Lidls were low power and poor quality.
Soapy water is OK to use directly in the tank, but removing solvents or aggressive cleaning chemicals can become messy.
A drainage valve or a removable tank would be useful for less spillage when emptying out.
The recommended method for using the nasty stuff was to load the tank with water, then drop an open top jar of cleaning chemicals into the water.
I could never get a satisfactory result with a jar in the low powered bench top machine.
Edit - I also needed to use a plastic dish in the bottom of the sonic tank to prevent the metal work from rubbing on the parts I was trying to clean.