I use the Kent Sea Squirt to feed my LPS. It's extendable to like 35" or so. ...
I use the same thing. It also doubles as my "wand of death." :lmao:
As far as tentacles not being out during the day, that shouldn't be the case with your Duncan. If it is, something ain't right.
Even if the acan/trachy tentacles aren't out, I bet if you squirt some food on them (and you ward off the shrimp with your 'wand of death') they'll appear pretty darn quick!