Another possibility is to use the Transform > Deform > Flow command to introduce tapering. That's where you'll surround the object with a cylindrical looking revolve (with a few more control points in it than a regular cylinder), and then make a second copy of that revolve edited to be tapered. Then select the object to be deformed, run Transform > Deform > Flow, select the cylinder surrounding it as the base surface, and the tapered one as the target surface. That will generate a tapering effect as in the attached file, it will allow you to produce the tapering in a non-uniform way.

Some of these kinds of things that squash surfaces down to some collapsed shape can somewhat easily generate a self-intersecting surface which then won't work very well with boolean calculations after that, that's something to keep in mind if you are going to try to intersect the surface in some later on step.

- Michael