I"ve had two versions of this effect over the years, and have used it to good ends. It's an easy one to learn, perform-good for walk around, and easy to carry. It is not advisable, to let spectators play with the coins AND the prop, before or after the effect. Examination of the cylinders and plug at end, may not even be necessary, as they can assemble all in the beginning of the trick.
A more advanced, and perhaps more magical looking version of this trick is Al Cohen's Coin Funnel. It's aluminum, looks a bit like a jigger, and includes a 'chop cup' type finale, not possible with quarter squeeze. While nicely made in brass, these cylinders always reminded me of garden hose washers-and are limited to this one single effect...thus binding it to 'a trick you can only buy at one of those magic shop places'. Aside from that, it's reliable and accessible for anyone not obsessed with sleight of hand. A bit of sleight work at finish, however, will help with the trick's finale.