Extreme Phono None-Felt Mat Residue

Greetings,

I recently purchased the donut style none-felt mat for my turntable. I like the sound of it as compared to the standard felt mat--much tighter across the board.

One major problem, though, is that it leaves a residue on my LPs. I have tried cleaning the mat with regular dish soap and water, followed by a brushing with some record cleaning solution. This did help a little bit, but the residue remains. I have tried to remove the residue from my LPs with a regular vacuum cleaning, but it hasn't worked. (I'll have to take the plunge and purchse the miracle record cleaner, I think...) So, my question is: how can I prevent the mat from leaving this residue on my LPs? Is there a better way to clean the mat?

I should note that I have been leaving my LPs on the turntable and mat for longer than is required to listen to them, and this appears to make a difference to what residue is left on them when I remove them. Still, short of always returning them to the sleeve, what can I do to prevent this problem?

-dan