I definitely heard that "acid" was used in some uxb's to dissolve the, presumably, plastic pre- igniter. But I didn't think that was used on V1's. From my memory, I'm sure that Grandarog's description is correct and the enormous area covered by their detonations really confirms that. BUT not completely as, & I speak from experience, sometimes the engine cut out but the V1 continued an onward glide. Specifically, on one occasion I was fishing with a friend in one of the Hoo area chalk pits & a V1 motored up to directly above & -Silence- just like that! (As they all were that I heard, stopping in mid sentence so to speak). Expecting it to dive into the pit, we'd have had a first hand view, but no, it just carried on, heading for London on quite a shallow glide path into the distance. I'm still in touch with a couple of RAF Halton Armourer Apprentices, 1947 onward, who would have covered all aspects of bombs & fuses in their 3 year course. I will ask.