rarely, I think. When you need to get really deep or deep really fast (a fast flowing river with a pocket of fish) as examples. Otherwise, a sink tip mated to an intermediate or floating line seems to be preferred. But I am also interested in learning what others think
Yes, a clouser with lead eyes on a sink tip line should work. A fly line with interchangeable tips might be the most economical approach. Rio makes a versitip line. I have the 8 wht. but you could add a sink tip to a 10 wht line to get a weighted fly down there.