Thanks for the hint,
yes, ultimately, I will simply withdraw/show the widgets until that part of the programme is finished. The destroy part was more or less an easy thing to do as a proof of concept.
If I can't find a better solution, I will probably have to create dedicated widgets for each instance, but that somehow seems to be a very clumsy way of doing it and I was hoping to simplify the code by re-using the widget calls.