i, too, have found that actors really want to know what they said wrong. after the bajillionth time that someone said "but what did i say instead?" i finally added it to my line notes. from then, it became a habit. and every time i hand out that first set of line notes, i hear "oh wow. you wrote what we said? that's so helpful!" and it really does seem to help.
i've also created a shorthand to quickly notate most things in my book, so the only words i really write in are their "creative interpretations" (read: the words they completely make up) after rehearsal, i type them all up in Excel and email em out as attachments and/or provide hard copy, depending on the group & what helps them more.
i also really really really try to include the full correct line, no matter the length, which is especially helpful for the actors once they're past the point of carrying their scripts around with them. the negative side of this is that it takes more time to complete. i recently spent almost 11 hours doing one night's worth of line notes. (this however, is most certainly not the norm. the cast was having a particularly awful time with their lines at the beginning. ugh.)
overall, if the time is available for taking this extra step, it seems to work wonders, at least with the casts i've worked with.