Non-Bio of course .As Victor said, but use washing soda with a good squirt of washing up liquid.
Why? The alkaline washing soda should turn the wax to soap (saponification) and the washing up liquid prevents a lot of the scum.
In your bucket with hive tools etc. try a strong solution of washing soda, then see the difference that a shot of washing up liquid makes.
Same principle. I have no doubt that Victor's advice is anything but sound and would welcome a comparison from anyone that has cleaned a capping's bag using both techniques
Victor, does your detergent refer to bio or non-bio detergent? Us radio amateurs always need to deal with the detail, don't we, as it potentially makes a difference? I, currently, have no wax bag cleaning experience.