Manitario, I used LA’s Totally Awesome all purpose cleaner. Works great and is inexpensive.
After getting this plane I think the problem is the user knowledge and not the plane. The complaint I have most often seen is the mouth opening is too big to take a fine shaving, actually the mouth will close up as tight as any other plane. You have to remove the tote to access the third (hidden) screw that holds the frog assembly.
Added a pic to show the screw in the OP.