They do require a "hockey" helmet. We've been told the Gretzky bucket is a Broomball helmet, which shouldn't be worn in our USA Hockey sanctioned adult leagues. Anyway... back on topic...
I think people have this misconception that the ice is like a foot thick. I had a guy in a beer league game I was reffing there throwing a fit because I sent him off the rink until he put on a helmet intended for hockey (instead of his Gretzky bucket).
If you think the sharpener may be the issue, there is a kid named Jim at the proshop at Kettler in Arlington that does a great job. Kind of a hike from Rockville, but if you're in the area, he does a really nice job.
A couple pics of my recent acquisitions. Bauer 4 Rolls NBH 4 Rolls (picked these up from Rangers1234) with MSH2 palms CCM U+ Pro Reloaded Skates The rest of it airing out after pickup today