How to (effectively) remove random rows from datatable

I need to simulate randomly missing values from the datatable. How can I do this effectively? I've tried the following way, it works ok, but extremly slow.

Column Splitter, splits the class column from the attribute columns, Java Edit Variable returns a pseudorandom value from 0 to number of rows, and Row Filter removes row indicated by this variable, this is recrusively repeated for n times.

http://obrazki.elektroda.pl/1926093600_1430421257.png

If you want to remove random rows, just use the row sampling node.