I guess in order to hybridize them, you'd have to figure out how and when they're pollinated, do it yourself, and then isolate the hand-pollinated plant from further contact, collect seeds and grow them out.

I don't know if it's fact or not, but I have it in my mind grasses are wind pollinated. With the exception of Luzula nivea (Snowy Woodrush) I've never seen bees on my grasses.

It seems the steps would be:

Collect pollen from one grass (How, I have no idea).

Transfer it to the appropriate part of the other grass (How, I have no idea).

Isolate the pollinated plant from further pollen attacks. Cheesecloth wouldn't do it. You'd have to use some material finer than that, but still light, air and moisture transparent.

Wait for viable seed, and collect it.

Successfully germinate the seed and grow out the results.

Sounds like quite an undertaking.

Obviously, it varies from genus to genus, but the basic procedure would be to remove the anthers from the grass you'll pollinate, so they can't do the deed themselves.

Then take an anther from the pollen donor, and rub it on the stigma of the recipient.

Then the hard part. What material could you use to isolate the recipient flower from further pollination?