Maybe tap after what you want to delete and go from there backward?

found this, it's for HP touchpad, but probably most work much the same..

[If you hold the Delete Key long enough it will begin deleting one letter and the progress to whole words. If you want to speed things up...hold down the Shift Key and Delete to get that backspace a hopping.]
http://forum.webosroundup.com/index....dden-keys.481/