I tested it in training mode, on Jin. Explosion doesn't seem to catch any tech whatsoever, forward, back, neutral, you name it. So, unless your opponent jumped up blocking, that might work. But it would be the jankiest gimmick ever. It might work if they're playing a real fatty character though, I didn't bother to test that. :3
And if they weren't barriering the jump block, you could just hit them with an air unblockable anyway.