Some will insist that if the back of the hand is involved then technically it is a "hand-squeak". I do both lip and hand squeaking, with the hand-squeak being a lot louder and carrying a lot further, but not being as convenient as it doesn't leave both hands free.
Not too shabby PiedPiper. Having only listened to the first one as your download took awhile, I'd say you're definitely on the right track, actually the higher pitched portions are pretty good.
In my observation coyotes will stop and look, but rarely abandon all caution and make a beeline for ya, until the squeaking gets really high-pitched, say over about 18KHz.(I typically start out a little lower and progressively increase the pitch.)
Once a feller can consistently hit 20 KHz and sound like a gopher getting constricted by a snake, after the first few times of calling a bobcat or fox or coyote to 20 feet or less with nothing but the 'squeak, he'll wonder what all the fuss is about concerning ecallers. (Some might never even look back).
LionHo