I used one at work for cleaning mainly small metal parts, admittedly already quite clean, and the proprietary detergent didn't appear to be anything very special that washing-up liquid would not match.
Any specificity would be in material, not item; and there might be fluids appropriate for certain things like printed circuit-boards. Best source of information on that are the stockists of the plant and fluids – they want to sell you it but despite the "use outside our control" caveat, it's in their interest to help customers to select wisely.
The bath I used had a heater which helps the action and speeds the drying time.