I've seen the lengthy threads on do they or don't they, prep, what to hit them with and I've had and discarded several $25 cheapos that did nothing.
So I just want to say that in my 3" thick SYP bench top, 3/4" spade bit drilled with a cordless at no particular phase of the Moon dog holes, the $40 buck pair hold like ___________________ (simile of your choice) and take some effort to release. All the prep I did was what Gramercy recommends, a little round 'n round with some 60 grit paper.
Along with a $10 card scraper, the most cheap skate Neanderthal tool of all. Better even, you can't hit the scraper with a hammer!