Different ways to hold the slide
The sleeve slide is held in three different ways: with the little finger, the ring finger and the middle finger. The other fingers are used to steer and hold the slide. With the slide on the pinky position you still have three fingers, which can make chords in between. Guitarists who play a lot of notes use the ring finger because it gives them more grip. Playing slide with the little finger takes more practice.
Below are some guitarists who play with their pinkies.
Some guitarists who play with their ring finger.
Different ways to hold the slide (lap)
Slide guitarists, who hold the guitar in lap position, where the slide is not put on the finger but is slid back and forth over the strings from above.
John Hiatt & Jerry Douglas
Robert Randolph & Steve Ray Ladson
Sources: happy bluesman, tdpri.com, Thomas Moon: The Verdict Of Big Joe Williams, weeniecampbell.com, BBC news, Talkin' to myself: Blues lyrics, Michael Taft, digitalcitizen.ca, federalcigarjugband.com, pancocojams.blogspot.nl, americanbluesscene.com, YouTube, Wikipedia, Hudson Motors Compagny, Archive Minneapolis, The Cruel Plains, M.H.Price a.o., truewestmagazine.com, The Austin Chronicle, Cambridge Free English Dictionary, Oxford Dictionary, TheSaurus.com, dragonjazz.com/grablue/blues_travel, Encyclopedia of African American Popular Culture, Blues by Paul Breman, Blues by David Harrison, Quora.com, urbandictionary.com, Blogs.loc.gov, The Ballad Hunter by Alan Lomax, Black Pearls: Blues Queens of the 1920th by Daphne Duval Harrison, jopiepopie.blogspot.nl, redhotjazz.com, The Blues Lyrics Formula by Michael Taft, American Ballads and Folk Songs by Alan Lomax and John Avery Lomax, The Past Is Not Dead: Essays from the Southern Quarterly by Douglas B. Chambers, EarlyBlues.com, railroad-line.com, Jason Lee Davis' RailFan Pages , centertruthjustice.org