my g/f and i reviewed the spartacus clit clamp, and i'd definitely agree with trying clothespins first. the Y-style clamp is really heavy and while the adjustability is great in comparison to say bull nose clips, i found the clamp to still be a little unwieldy. takes a lot of patience and lots of communication. we've found that with a clamp as heavy-duty as the spartacus, there is a very fine line between pleasurable pressure with slight movement and Ohmygodgetitoffme!
if clothespins aren't tight enough for you, you can always treat the spring with a flame for a few seconds (careful not to set your house on fire, of course) which will stiffen the coil.