To get rid of the stickness just play the things ..it only last for a week or less.
+1,000 - I found that most rounds and flats I get change in 'tackiness' once I get them well coated in my finger juices . . . flats even more so. Chromes take about a month of moderate playing to break in IME.
Let me throw in GHS pressure wounds. I have two basses strung with these. A little more round wound zing in the tone...but feel a lot like flats.
Labella's are still my fav for deep sounded flats...but the pressure wounds are growing on me.
Pressure wounds are cool sounding strings - but more like a dark round than a flat IMO - you can get flat-ish sounds out but once you've had flats they don't compare, esp. for picking. They are better for a JPJ sounding crunchy pick sound IMO though - I'm a great believer in a right string for the task!