I use sinteres lap if I am working on a competition stone. I purchased the sintered laps after ruining my plated solid steel laps after when I took action on some very bad advice. The bad advice I got was to use Aluminum Oxide Dressing Bars to expose more diamond on the plated laps. The aluminum oxide dressing bars are made from, of course, aluminum oxide, which is the second hardest mineral, 9 on the Moh’s Scale. The bars basically stripped the plating and the diamond that was supposedly being held in place by plating.
These dressing bars are actually intended to be used on sintered laps, not on plated laps. I have a dedicated bar for each of my singtered laps.
When ever the lap looses its aggressiveness or starts to leave scratches turn the lap on slowly, give it lots of water and drag the dressing bar across the lap with minimal pressure till the water appears to become cloudy. Then remove the dressing bar, and rinse the lap thoroughly.