boogieman
It don't mean a thing if it ain't got that ping.
Did you use a fresh blade and keep the tip cool while cutting? Techno duds are pretty susceptible to expanding if they get heated up. They are quite cut resistant and you basically need a new blade. Also you have to let the blade do the work and not force it. You can also try to cool them, I forget the instructions (they come on a sheet with a tip, water maybe?). I'm not arguing with your experience but in my experience "floaters" and "sinkers" really don't mean anything when milkdudding tips. A "bad" tip becomes a good tip once it is soaked and compressed. A "bad" tip may not be exactly as good as a "good" tip but the difference once dudded is minuscule.I just installed a Techno Dud the other day for a customer at my shop and it was made from a bad elkmaster (90% of Elks are bad these days) and when I was done, it looked like Marge Simpsons hair! If the tip you start with is bad, you cannot press or chemically treat the bad out of it. If you'd like to try a Medium or Hard DM and I'll send you one to test.
Basically I'd venture to say 95% of expanding milkduds are due to installation error. The instructions that come with the tips are not just a suggestion, they should be followed closely. I've ruined one myself and it was because I wasn't using a fresh blade.
This would be the equivalent of someone complaining a recoil tip didn't have shiny sides because a customer shaped it with 120 grit sandpaper instead of using a blade as suggested.