Why not give your corys what they have in Amazonia? And that basically is playsand. The Quikrete tan/gray play sand is identical in appearance to the sand in many Amazon streams. Their colour patterns viewed from above over this sand clearly illustrates why; and they do take on their best appearance as a result. My 30+ corys are loving it.
I would not use any of the enriched substrates with corys or loaches. I was told this by a professional catfish importer who specifically mentioned Eco-Complete. When I decided to use an enriched substrate in my 70g I chose Flourite over Eco-Complete; I found both in a local store and was able to feel them in my hand, and EC was sharper and harder than Flourite. Howdever, now that I have Flourite, I have had to remove the corys from that tank, as it was definitely bothering them with barbel issues. They went into the larger tank with sand, and made a noticeable improvement.