I use a wine bottle neck cut down. Any where from 2.5" to 1". They are pretty thick.
Search: willy's slides
Willy will make a slide to meet your needs.
There's a short (stubby) version in both medium and narrow diameters although MF doesn't appear to carry both.
I like Willy's slides, advertised right here on the nation. My momma say God heps them who heps themselves.
Hey, Eric! Did you ever hep yourself to some slides? What worked?