advice on removing mcD pony tails

[CarnationTwirl]

I'd like your advice on removing the hard tails from McDonald ponies to create a nice smooth finish.
What I've done in the past is dunk them in boiling water and hacked away with a hobby knife.  Very tedious, very messy, and leaves rough edges.
I've come into possession of a rotary tool (off brand variable speed) and like, hundreds of bits for it.  I'm not sure what bit would be appropriate for this purpose though and there's sooo many to try!  I did try a cut off wheel but that just melted the plastic before ultimately shattering (yay safety glasses!)

I'm getting sick of having to patch up the roughness.