I would like to find a flanger pedal that is capable of very slow rates. Or maybe I should say very long rate times. That is, a flanger that would take, say 8-10 seconds to complete a whoosh cycle. I have an EHX Deluxe Electric Mistress, and it has great sounds for faster rate flanging, but it's not capable of very slow rates. Is there such an animal out there? Or is that only obtained in expensive studio rack effects?