Well, the whole point of provoking an AoO is that you're doing something that gets in the way of fighting and protecting yourself. If you look at it that way, it isn't the magic of the potion or extract, it's the action; and the action is the same for both.
I agree with knightnday. So long as the knitting doesn't get in the way of playing let it go. Particularly if it's a large group and people have to sit around waiting. Otherwise they -will- talk, check their phones, or something else that -will- get in the way of the game.
The whole point of this is to have fun. If we turn it into a religion by taking it too seriously it isn't fun any longer.
OTOH, if you're going to let bags of flour work you ought to let arrows work. Really the same idea. Though I have shot an arrow completely through a deer and have had an arrow shatter and bounce out after hitting a shoulder bone. Why not give them a percentage chance of it working? Maybe 50% or 25% or something.