Off-hand friendly directed fire (not counting area effects) is completely forbidden, which would cover swarm attacks.
So no, there's no way to move Elementals with standard mechs unless you allow custom units and modify them with magclamps (missiles to magclamps is quite doable modification), or should we ever get such modified Elemental variant.
There is one Clan battle armor that does have magnetic clamps: The Stormbird (Jade Falcon). It is not quite Elemental replacement, being a heavy armor, but it does give second-line Clan forces an option.