Dispel magic is the only(non suicidal) way to blow through a wad of ER. and it would be a min CL 5... though there was a way somewhere to work it.
oh yeah, no it is on a gliph of warding lesser(gotten from a geometer dip) while you are holding CL-1 opposed alinement arrows. You fill the gliph with a dispel magic(at your current CL of 1), and when the seal is broken it fires off.
It costs you a charge of a level 3 spell wand, but it is so worth it. Have it on a closed letter, and use an unseen servant as the delivery system.