you might find that the fawn in destress would work best. do you have a spot light and can you hunt at night? because that will be you best time to see them. i find a lot of times areas where we deer hunt don't have a single print on them. and if we have 2 or 3 gut piles out there the next morning their are yote tracks all over. here in PA we can't hunt coyotes at night during deer season so i would check your law book.

my most perductive way so far to hunt a pile is to get out 1 or 2 days later and use a fawn in destress. however the woodpecker in destress call has also worked well for me.

howling may work i'm not sure. never tired it over a pile because i was always afriad i may put the deer on high aleart. i don't know though may work really well and not bother the deer at all. i would try yelps instead of howls as well
good luck