No there is no reason why you can't use it with jalapenos IF you really want dilled jalapenos. The sweet pickle mix and the bread and butter mix are flavors that are far more compatible with jalapenos for most folks.

Dave

I was thinking they'd be kinda liked pickled jalapenoes.... The kind you put on nachos or subs?

They would be except for the dill. If you look at all the Pickled Peppers recipes for the ones like you refer to you'll see they are normally made with some sugar, mustard and celery seed rather than dill. Dill tends to give hot peppers a bitter after-taste. But it's your choice.

Dave

If you want pickled jalapenos, just find safe directions for them and make them. I've pickled peppers and it's just as easy to make them from scratch as try to use a mix. Basically it's vinegar and peppers. I agree with Dave, dill and hot peppers don't sound very good.