I think blades aren't really an issue. They spin under the Grill, so all they encounter are leaves sticking through the grill. I don't put sticks in it. Main bud is cut off close to the bud, as are the smaller one underneath.I’m doing that all the time… so I guess the blades last a while? I can see where neglectful cleaning would not help either. Seems that they would have gotten dull on that last sticky batch I grew. Maybe would have broke it. If it has a washer to hold the blade on, you could try a recessed washer to bring it up a bit more…
Bubba