Paul, You say "I spotted this quick and easy way to make a dowel end: "... and, in fact, you did just the ends of those sticks...
But these jigs really shine at making any length dowel, and any diameter you might need. Metric dowels, sure! The exact size to fit into that pipe, awesome!
Use a hand brace or in a power drill.
They make a nice swoopy transition between the tenon and the native material. Looks like they would not have any hang-ups with any little knobbins or knots either.