Do you need a separate picnic tap than your normal serving tap? i.e. can you pull the modified bottle filler out once you are done or is it jammed in there so well that it's stuck or you'll break something?
You can use any picnic tap just be careful when you insert the racking cane. I made the mistake of pushing too hard and broke the plastic lip on my picnic tap. It doesn't have to be all shoved up in there- a gentle push is all that's needed.