Give these a look: http://www.growstone.com/
I found the performance of these to be equivalent to hydroton, with the benefits of being MUCH lighter, easier to wash initially. The jagged edges (think lava rock, or pumice texture, but lighter and maybe a little sharper) make it very inhospitable for soft bodied insects-- I think this was key in a successful eradication of RA in a large growroom, which I had battled for consecutive rounds in a coco DTW setup. I also tried Met52 and the standard suggested chems (Evergreen 60-6, Merit 75, Botanigard, etc) . I cleaned house, switched to and Ebb/Flood bucket system (which I had lots of experience with in the past, but hated the hefting of hydroton), and switched to growstones, never saw the RA again.
In the French wine blight of the mid 19th century, caused by phylloxera (root aphids), it was observed that vineyards on sandy soil suffered less damaged. Growstones are made from recycled glass, and glass is made primarily from quartz sand, so there is some history to the suggestion that a glass-based medium would deter a soft bodied insect looking for a cozy environment to breed and eat in.
Another note: Ebb and Flow style setups make it easy to do a complete drench of medium with chemical treatments as compared to top-feed or hand watered setups, and can greatly reduce how much contact you must have with the pesticide you are applying.