Honestly if the quick-release is all crapped up with salt or sand or road-grime, I'd just try rinsing it off with water. Warm soapy water, perhaps? Then try to work it off slowly.
Make sure you're pulling the clip away from the hose connector correctly, as shown in this small YT video:
Rinsing something on the underside of the engine compartment won't be easy. I'd use a spray bottle of some sort to get the water right in there where it needs to be.
Good luck, & stay calm. I broke a radiator hose connector when I got a bit over-strenuous trying to un-stick it -- I couldn't use my car for a few days as I waited for a replacement part to come in!