I don't want to remove the parameter page, I was just trying that to see if that would remove all parameters.
Yes, the params in question are Strings and I use them in a call to a list-view (Pega 6). As I'm having multiple calls to the list view and I'm preparing the parameter page ahead of the calls, I need to dump individual params from the page. See, there's a difference when calling a list-view with an empty, but existent parameter or without the parameter's existence. Seemingly, in the latter case, Pega leaves out the corresponding part of the WHERE-clause. At least according to my analysis.
Unfortunately, it doesn't do so for me (Pega 6.3?). I have been tracing through an activity and if I set the params in questions to an empty String, they still exist in the Parameter-page in tracer. Thus the call to the list view (see my reply to Pankaj) sets the WHERE-clause and therefore yields other results.
I have the feeling I could achieve this on a Java / function basis, but wonder if You have seen a possible implementation already?