Duragilt and Duracomb are a prodcuts from Dadant. both are a smooth piece of plastic with a thin sheet of beeswax on each side of it that is embossed just like wax foundation. It looks like wax foundation. The Duragilt has the addition of the metal edges and the communication holes. If this is what your foundation looks like it may be difficult to crush and strain without ruining the foundation. You could try to use a knife to cut the combs very shallow, but the wax often comes loose from the plastic if you get too deep. Once the wax comes off of the plastic the bees will never rebuild comb on the plastic.
Ritecell, Plasticell, Pierco and a few others are molded plastic foundation. In other words the cells are embossed into the plastic with cell walls sticking up from the plastic. These you can scrape down to the foundation and the bees will happily rebuild it.
If you intend to do crush and strain from the start, your best bet is a starter strip, foundationless or thin surplus wax with no wires. Then you can make cut comb or crush and strain. You don't need foundation, you just need a comb guide of some kind, such as the starter strip or a triangular piece on the top bar. But the "typical" way this is done is to just use wax foundation with no wires.
Plastic foundation, including Duragilt, and wired foundation, was invented for brood comb and extracting, not for comb honey or crush and strain. Comb honey is typically thin surplus foundation.