I always swallow LSD, maybe chew on it for a bit first. It takes ~45min to start working. An acquaintance took a 150ug tab of GDF Fluff (what I normally take). He left it on his tongue, and said he felt the extreme effects within minutes, and said he couldn't see, nothing even resembled his actual surroundings, etc.. I've taken these exact tabs probably 10-15 times, and when I do, nobody would even know unless I told them. (aka I act straight and can hold a conversation very easily, but still experience amazing effects) Could him leaving it on his tongue have made THAT much of a difference? I think maybe the LSD on the tabs I received wasn't distributed evenly and he may have gotten like 400ug... I don't really know how else to explain it.
It shouldn't, keeping on your tongue and swallowing it is just about the same thing, they both get absorb the same way. I always swallow mine to make sure I'm getting LSD because NBOMe doesn't activate with you swallow.