I've also got the oasis deflators and they are the nutz. You'll have to keep a close eye on them as your buddies will try to cheat you out of them
They work great, set them and forget them. Although some put them on and drive onto the beach while they are working, I completely air down before driving on the beach, and remove them. I think they would pick up alot of sand if left on the valve stem, but thats just me.
As also noted, black binder clips with screws can be made for next to nothing, just dont get distracted or you'll have flat tires. Might be a good idea to use them close to, but not blocking, the air station, just in case.
regardless of which way you go, you'll need a tire pressure guage. I carry 2 in my bag. One is a low pressure guage with a top reading of like 25-30psi and the othe is rated up to somethink like 60. I use the first to airdown because I think its more accurate than th one rated for hight pressures.