I would prefer something a bit more mobile. And I worry about using a fence against a cloud. It probably has about as much chance of working as anything, so it is not bad, and we left ourselves in this ridiculously horrible situation with an aircraft that, as predicted, loved to go into unrecoverable dives when confronted with inclement weather, and desperate for a great roll that somehow converts our entire army into antimagic immunity... I would, however, rather like to separate ourselves from our extreme dependence upon being inside glass houses... Also, as much as I genuinely love the Faraday cage reference, I am a touch concerned about the viability of the described action.
Faraday cages do not "block particles", it is more of a channelling effect, and with good reason. We are trying to stop a cloud with bars. Clouds go through bars, and the bars are made out of material that has proven prone to being dispersed by antimagic. I feel as though our existing antimagic resistance on our crystals is more of a "hiding" effect than an "immunity" effect. But this concern is not well substantiated so hopefully is not an issue. We need something that acts as a conduit to antimagic and, well, the Faraday cage works because electricity is looking for a path to go from one place ot another, the antimagic clouds are happy to just loiter, we really need some form of active suction...
I also worry that we really don't have any experience in getting crystal to respond to magical energies. We have crystals that conduct or resist mundane forces, and want to get crystals that attract and control magical forces out of a revision. I just find it kind of unfortunately risky to make what seems to me to be rather a large leap.
Antiantimagic charms
We know that Kegger antimagic is different to our own. It extinguished our crystals when our own antimagic did not, which proves that, while our own antimagic can completely drain a region of magical potential, their's actually engages with magical presences and forces them to cease. We can see from this that it is definitely an active effect, imposing itself forcefully, where ours is a passive effect of simply draining the magic as the magic becomes active.
Another major observation that we have is that Kegger antimagic has no interaction with our own. The visible fields happily passed over our charms without any effects. This demonstrates that whatever it is, it is not a free-floating magical effect. This would suggest that it is not, in fact, magic. But we have seen that stabilised magic can maintain its integrity within an antimagic field from the performance of our own fireballs and crystals. There are no reports of our antimagic charms being damaged in any way from this... It seems that the Kegger antimagic is somehow stabilised magic in its field form. Which is ridiculous given its variable size and shape. It is clearly being modified actively while in progress, so must be escaping from our antimagic in some other way...
Finally, we have seen that the Kegger antimagic is produced by seemingly-magical staves from definitely magical wizards, and yet, despite its toxicity to crystal constructs, it has no effect on these staves, and has no long-term detriment to any of their other magical equipment.
From this there has been much speculation, but it seems that only one explanation fits all of the criteria. That of this "antimagic field" being thus:
A sustained magical effect with a fundamentally mundane nature. Its mundane nature allows it to behave as a mundane force, thus not being absorbed by our charms while it imposes mundanity within its influence, yet it is still clearly a magical construct, performing feats that are clearly impossible in the absence of magic, namely being stable in an inherently unstable shape. It is a small thing, but any builder can plainly see that such a cloud would collapse and disperse regardless of how immaterial it were, and certainly wouldn't adjust itself to the whims of a controller...
Thus, it is clearly magic, just of an extremely exotic form that our charms are not attuned to. No doubt there are other exotic forms of magic that our charms may also be incompatible with, which may lead to later developments of magical forms which can be used while wearing a charm, but for now it should be a rather simple matter of going over the mathemagics of charms and tweaking them to respond to the overtly mundane. Given the function of the charms, that they merely absorb magic, they should still be unable to damage anything that is legitimately mundane(although very careful testing with failed or low-potential applicants to The Academy is advised, lest we unknowingly distribute an effect that can permanently strip the magical potential from a mage) but should now be able to absorb this mundane-themed magic as well as it does any other. Given the broad and unfocused style of Kegger antimagic, it should be a simple matter to have a single charm steadily drain an entire field, and thust prevent it from crossing a certain point. Thus we can defeat their antimagic by simply sticking an antiantimagic charm between whatever is to be protected and the source of antimagic. Be that gluing one onto a protector or mounting it on a stick and holding it in front of some wizards.
In short: We change our antimagic charms so that they do the antimagic thing to antimagic fields. Being fields, you just need to get it into one point to suck up the whole field as though you were deflating a balloon...