I should have known better, and I'm almost ashamed to admit that I thought I could get away with using such a product.
I bought some #60 paper at Harbor Freight. It's right down the street from me, so it isn't like it's out of my way to go there.
The name brand is Gator Grit. The stuff is real trash, and I'm glad that I only bought one package because this stuff is a total waste of money. No, it doesn't clog up. It doesn't have enough bite to last long enough to clog up. From now on, I'll get 3M from wally world.
In a more postive side, I bought some #600 and #1000 wet/dry from harbor freight. The stuff dies quickly, but you can get a 20 pack of full sheets for about $5. When you go to wally world and buy similar grit 3M paper, you pay 5 or so bucks for a 3 to 5 pack of half sheets. The soulution to this is to just keep chucking it away every 2 minutes.